Answer:
pH at equivalence point is 8.47
Explanation:
Benzoic acid react with NaOH, thus:
HC₇H₅O₂ + NaOH → C₇H₅O₂⁻ + H₂O + Na⁺
You reach equivalence point when moles of the acid = moles of NaOH.
Moles of benzoic acid are:
0.025L ₓ (0.0988mol / L) = 0.00247 moles
To have 0.00247 moles of NaOH in solution and reach equivalence point you need to add:
0.00247 moles NaOH ₓ (1L / 0.115mol) = 0.0215L of NaOH solution.
Total volume is 0.0465L.
There are produced 0.00247 moles of C₇H₅O₂⁻ and its molarity will be:
0.00247 mol C₇H₅O₂⁻ / 0.0465L = 0.0531M C₇H₅O₂⁻
C₇H₅O₂⁻ is in equilibrium with water, thus:
C₇H₅O₂⁻(aq) + H₂O ⇄ HC₇H₅O₂(aq) + OH⁻(aq)
Where Kb = Kw / Ka = 1x10⁻¹⁴ / 6.5x10⁻⁵ = 1.54x10⁻¹⁰ is:
Kb = 1.54x10⁻¹⁰ = [HC₇H₅O₂] [OH⁻] / [C₇H₅O₂⁻]
The concentrations in equilibrium of the species are:
[HC₇H₅O₂] = X
[OH⁻] = X
[C₇H₅O₂⁻] = 0.0531M - X
Where X represents how much C₇H₅O₂⁻ react, X is reaction coordinate
Replacing in Kb expression:
1.54x10⁻¹⁰ = [HC₇H₅O₂] [OH⁻] / [C₇H₅O₂⁻]
1.54x10⁻¹⁰ = [X] [X] / [0.0531 - X]
8.169x10⁻¹² - 1.54x10⁻¹⁰X = X²
8.169x10⁻¹² - 1.54x10⁻¹⁰X - X² = 0
Solving for X:
X = -2.858x10⁻⁶M → False solution, there is no negative concentrations
X = 2.858x10⁻⁶M → Right solution
As [OH⁻] = X
[OH⁻] = 2.858x10⁻⁶M
pOH is -log [OH⁻]
pOH = 5.54
pH = 14 - pOH
pH = 8.46
pH at equivalence point is 8.47Consider 1 M solutions of NaCl, ethyl alcohol (CH3CH2OH), and hydrofluoric acid. Rank them in terms of how well they conduct electricity and explain why you ranked them this way.
Answer:
conductivity increasing order CH₃-CH₂-OH < HF< NaCl
Explanation:
NaCl is the better conductor comparing with remaining two. it is strong electrolyte. dissociation percent always nearly eqaul to 100% but HF is weaker acid than NaCl and dissociation percent <100% . So, the no of ions furnished by HF less than that of NaCl
CH₃-CH₂-OH organic compound . in general it is not treated as an electrolyte and it cannot carry any charge. If it carries, it is very very less compared to remaining two
Many free radicals combine to form molecules that do not contain any unpaired electrons. The driving force for the radical–radical combination reaction is the formation of a new electron‑pair bond. Consider the formation of hydrogen peroxide. 2OH(g)⟶H2O2(g) Write Lewis formulas for the reactant and product species in the chemical equation. Include nonbonding electrons.
Answer:
In the attached image the Lewis equation is shown where it is shown how two oxygens react with two hydrogens to meet the octet of the electrons.
Explanation:
Hydrogen peroxide is one of the most named chemicals since it is not only sold as "hydrogen peroxide" in pharmacies but it is also one of the great weapons of immune defense cells to defend ourselves against anaerobic bacteria.
The disadvantage of this compound is that when dividing it forms free oxygen radicals that are considered toxic or aging for our body.
In the attached image below, you will see the Lewis equation is shown there. There, you will see how two oxygens react with two hydrogens to come about the octet of the electrons.
When two or more atoms bond with each other, they often form a molecule. When two hydrogens and an oxygen share electrons through covalent bonds, a water molecule is formed.
The octet rule is known as when most atoms want to gain stability in their outer most energy level by filling themselves that is the S and P orbitals of the highest energy level with eight electron.
HOOH is the compound that is form. It is called Hydrogen peroxide. This because it is has reactive oxygen species and the simplest peroxide.
Lear more from
https://brainly.com/question/15715780
What is the shape of a molecule that has 4 atoms bonded to a central atom
and no lone pairs of electrons?
A. Octahedral
B. Cubic
C. Tetrahedral
D. Trigonal-pyramidal
Answer:
C. Tetrahedral
Explanation:
Tetrahedral would be the correct choice because the central atom has 4 domains (1 bond counts as 1 domain so 4 bonds =4) and no lone pairs which means it has tetra (which translates to four) domains hence tetrahedral.
Tetrahedral is the shape of a molecule that has 4 atoms bonded to a central atom and no lone pairs of electrons. Hence, option C is correct.
What is an atom?An atom consists of a central nucleus that is usually surrounded by one or more electrons.
Tetrahedral would be the correct choice because the central atom has 4 domains (1 bond counts as 1 domain so 4 bonds =4) and no lone pairs which mean it has tetra (which translates to four) domains hence tetrahedral.
Hence, option C is correct.
Learn more about atom here:
https://brainly.com/question/1566330
#SPJ2
The distance from the Moon to Earth is 5.46 * 108 km. How long does it take a laser need to travel between the moon and earth?
a. 1.64 X 1020 s
b. 1.82 X 103 s
c. 1.82 s
d. 0.182 s
e. 1.64 X 1017 s
Answer:
B. 1.82(10³) seconds (1820 seconds)
Explanation:
Speed of Light: 3.00(10⁸) m/s or 3.00(10⁵) km/s
We know the distance from the Moon to Earth as 5.46(10⁸) km
We simply divide the distance by the speed of light:
[tex]\frac{5.46(10^8)}{3.00(10^5)}[/tex]
We should get 1820 seconds or B. 1.82(10³) as our answer.
Which of the following is NOT a type of crystal structure? A. None of these B. Metallic C. Ionic D. Macromolecular (giant covalent)
Answer:
A. None of these.
Explanation:
A crystal structure is an arrangement of atoms or ions in a repeating three-dimensional array.
B. is wrong. Metal atoms, such as gold, arrange themselves into a crystal structure.
C. is wrong. Ionic solids, such as sodium chloride, arrange themselves into a crystal structure.
D. is wrong. Macromolecules (network solids), such as diamond, arrange themselves into a crystal structure.
The correct answer is None of these.
What is a crystal structure?A crystal structure is a three-dimensional collection of atoms or ions that repeats itself.Metal atoms(gold), Ionic solids (sodium chloride), and Macromolecules(network solids) arrange themselves into a crystal structure.Learn more about crystal structure here:-
https://brainly.com/question/23986315
#SPJ2
Name MgSo4.7H2O /Cs3PO4.H2O
Answer:
MgSo4.7H2O = Magnesium sulfate
Cs3PO4.H2O = Cesium Phosphate
Hope this helps!
To condition the buret, add a small volume of ____________ to the buret and rotate the barrel ____________ so that the liquid makes contact with the full inner surface of the barrel. Complete this action _________ and discard each volume in a designated waste container.
Answer:
Acid, Horizontally, Drain off the acid by opening the stopcock
Explanation:
A buret is a calibrated glass appratus used to measure and deliver accurate volume of liquid, usually acids, in acid-base titrations.
Before usually the buret to carry out your titration reaction, it is advised to condition or prepare your buret for use.
To condition the buret, add a small volume of the acid to the buret and rotate the barrel horizontally to ensure that the liquid ( acid) makes contact with the inner surface of the barrel o the buret.
This procedure is done to wash off any previous acid or liquid that the buret had been used for in previous titrations.
Complete this action by opening the stopcock of the buret to drain off the acid and discarding each volume in a designated waste container.
Note that acids could be corrosive and dangerous to the skin and so should be handled with great care
. Explain why, in the sample calculations, 0.1 g of the unknown produced a GREATER freezing point depression than~e same mass of naphthalene.
Answer
Naphthalene is a non electrolyte
If the unknown compound is an electrolyte it gives 2 or more ions in solution
( NaCl >> Na+ + Cl- => 2 ions
Ca(NO3)2 >> Ca2+ + 2 NO3- => 3 ions)
the f.p. lowering is directly proportional to the molal concentration of dissolved ions in the solution )
For naphthalene
delta T = 1.86 x m
for a salt that gives 2 ions
delta T = 1.86 x m x 2
hence the lowering in freezion point of unkown is greater then napthalene
If the reaction starts with a mixture of PCl5, PCl3 and Cl2 at pressures of 0.820 atm, 1.322 atm and 0.911 atm respectively, is the reaction at equilibrium
Answer:
The reaction is not in equilibrium
Explanation:
For the reaction:
PCl₅ ⇄ PCl₃ + Cl₂
Equilibrium constant, Kp, is defined as:
[tex]Kp = \frac{P_{PCl_3}P_{Cl_2}}{P_{PCl_5}} = 0.497[/tex]
When this ratio is = 0.497, the reaction is in equilibrium. Replacing the pressures of the problem, reaction quotient, Q, is:
[tex]Q =\frac{1.322atm*0.911atm}{0.820atm} = 1.469[/tex]
As Q ≠ Kp, the reaction is not in equilibrium
To reach the equilibrium, the reaction will shift to the left producing more reactant and decreasing amount of products.
Write the empirical formula
Answer:
[tex]Fe(C_{2}H_{3}O_{2})_{3}\\Fe (OH)_{3}\\\\NH_{4}(C_{2}H_{3}O_{2})\\\\NH_{4}OH[/tex]
Explanation:
[tex]Fe^{3+}(C_{2}H_{3}O_{2})^{-}_{3}--->Fe(C_{2}H_{3}O_{2})_{3}\\Fe^{3+} (OH^{-})_{3}--->Fe (OH)_{3}\\\\NH_{4}^{+}(C_{2}H_{3}O_{2})^{-}--->NH_{4}(C_{2}H_{3}O_{2})\\\\NH_{4}^{+}OH^{-} ---> NH_{4}OH[/tex]
Identify the acid, base, conjugate acid and conjugate base in the following reactions:
a. NH_3(aq) + CH_3COOH(aq) NH_4^+ (aq) + CH_3COO^-(aq)
b. HClO_4(aq) + NH_4(aq) ClO_4^- (aq) + NH_4^+ (aq)
Answer:
a. NH₃ : base
CH₃COOH (acetic acid) : acid
NH₄⁺ : conjugate acid
CH₃COO⁻ : conjugate base
b. HClO₄ (perchloric acid) : acid
NH₃ : base
ClO₄⁻ : conjugate base
NH₄⁺ : conjugate acid
Hope this helps.
What is the electron geometry and molecular geometry of:
A. H2O
B. CH2CL2
C. OPCL3
D. CO3^2-
E. ALCL6^3-
F. SO2
G. PCL5
Answer:
H2O
Electron geometry-tetrahedral
Molecular geometry bent
CH2Cl2
Electron geometry- tetrahedral
Molecular geometry-tetrahedral
OPCL3
Electron geometry- tetrahedral
Molecular geometry- tetrahedral
CO3^2-
Electron geometry- trigonal planar
Molecular geometry- trigonal planar
ALCL6^3-
Electron geometry-octahedral
Molecular geometry- octahedral
SO2
Electron geometry-tetrahedral
Molecular geometry-bent
PCL5
Electron geometry-trigonal bipyramidal
Molecular geometry- trigonal bipyramidal
Explanation:
Water contains four electron domains this corresponds to a tetrahedral electron geometry. How ever, there are two lone pairs in the molecule hence it is bent.
CH2Cl2 is shows a tetrahedral molecular geometry and a tetrahedral electron geometry. This can only be observed from the structure of the compound.
OPCL3 is bonded to four groups making it a tetrahedral molecule. There are non lone pairs on phosphorus so the molecule is not bent.
CO3^2- is bonded to three groups which leads to a trigonal planar geometry.
ALCL6^3- contains six bonding groups which arrange themselves at the corners of a regular octahedron at a bond angle of 90°.
SO2 has four electron domains leading to a tetrahedral electron domain geometry according to valence shell electron pair repulsion theory. However, the lone pairs on the central atom in the molecule leads to a bent molecular geometry.
PCL5 has five electron domains without lone pairs of electrons on its central atom. Hence the molecule possess a trigonal bipyramidal geometry.
The electron geometry and molecular geometry of the molecule are as follows:
A. H₂O: The electron geometry is tetrahedral because it has four electron domains (two bonding pairs and two lone pairs). However, due to the presence of two lone pairs, the molecular geometry is bent or V-shaped.
B. CH2Cl₂: The electron geometry is tetrahedral. However, the molecular geometry is trigonal planar because two of the electron domains are occupied by chlorine atoms, resulting in a bent shape.
C. OPCl₃: The electron geometry is tetrahedral. However, the molecular geometry is trigonal pyramidal because one of the electron domains is occupied by a lone pair on phosphorus.
D. CO3⁻²: The electron geometry is trigonal planar because it has three electron domains (three single bonds). The molecular geometry is also trigonal planar.
E. AlCl6⁻³: The electron geometry is octahedral because it has six electron domains. The molecular geometry is also octahedral.
F. SO₂: The electron geometry is trigonal planar because it has three electron domains (two single bonds and one lone pair). The molecular geometry is bent or V-shaped due to the presence of a lone pair on sulfur.
G. PCl₅: The electron geometry is trigonal bipyramidal because it has five electron domains. The molecular geometry is also trigonal bipyramidal.
To learn more about the electron geometry, follow the link:
https://brainly.com/question/9651182
#SPJ6
At 25.0°C the Henry's Law constant for methane CH4 gas in water is ×1.410−3/Matm.
Calculate the mass in grams of CH4 gas that can be dissolved in 75.mL of water at 25.0°C and a CH4 partial pressure of 0.68atm. Round your answer to 2 significant digits.
Answer:
1.1 × 10⁻³ g
Explanation:
Step 1: Given data
Henry's Law constant for methane (k): 1.4 × 10⁻³ M/atm
Volume of water (=volume of solution): 75 mL
Partial pressure of methane (P): 0.68 atm
Step 2: Calculate the concentration of methane in water (C)
We will use Henry's law.
[tex]C = k \times P = 1.4 \times 10^{-3}M/atm \times 0.68atm = 9.5 \times 10^{-4}M[/tex]
Step 3: Calculate the moles of methane in 75 mL of water
[tex]\frac{9.5 \times 10^{-4}mol}{L} \times 0.075 L = 7.1 \times 10^{-5}mol[/tex]
Step 4: Calculate the mass corresponding to 7.1 × 10⁻⁵ mol of methane
The molar mass of methane is 16.04 g/mol.
[tex]7.1 \times 10^{-5}mol \times \frac{16.04g}{mol} = 1.1 \times 10^{-3} g[/tex]
please help me I am begging you.. )))): PLEASE HELP ME ~~~~~~~~~~~~~~~~~~~~~~ A football player experiences acute pain in his knee. Which of the following methods can a doctor use to diagnose the reason for the pain? --_-_-____- A.) Use infrared radiation from warm objects to look inside the knees. B.) Use radio waves emitted by radioactive substances to look at bones. C.) Use radiations emitted by very hot objects to penetrate the skin and bones. D.) Use x‒ray radiation to see if there are any fractured bones.
Answer:
D. Use x-ray radiation to see if there are any fractured bones.
Explanation:
The football player may have fractured a bone while he was practicing or playing, so it is best for the doctor to check if the player broke his bone or fractured it.
A solution is prepared by adding 6.24 g of benzene (C 6H 6, 78.11 g/mol) to 80.74 g of cyclohexane (C 6H 12, 84.16 g/mol). Calculate the mole fraction and molality of benzene in this solution.
Answer:
[tex]x_B=0.0769[/tex]
[tex]m=0.990m[/tex]
Explanation:
Hello,
In this case, we can compute the mole fraction of benzene by using the following formula:
[tex]x_B=\frac{n_B}{n_B+n_C}[/tex]
Whereas n accounts for the moles of each substance, thus, we compute them by using molar mass of benzene and cyclohexane:
[tex]n_B=6.24g*\frac{1mol}{78.11g}=0.0799mol\\ \\n_C=80.74g*\frac{1mol}{84.16g} =0.959mol[/tex]
Thus, we compute the mole fraction:
[tex]x_B=\frac{0.0799mol}{0.0799mol+0.959mol}\\ \\x_B=0.0769[/tex]
Next, for the molality, we define it as:
[tex]m=\frac{n_B}{m_C}[/tex]
Whereas we also use the moles of benzene but rather than the moles of cyclohexane, its mass in kilograms (0.08074 kg), thus, we obtain:
[tex]m=\frac{0.0799mol}{0.08074kg}=0.990mol/kg[/tex]
Or just 0.990 m in molal units (mol/kg).
Best regards.
Considering the definition of mole fraction and molality:
the mole fraction of benzene is 0.077.the molality of benzene is 0.9908 [tex]\frac{moles}{kg}[/tex].You know that:
Mass of benzene = 6.24 gramsMass of cyclohexane= 80.74 gramsMolar mass of benzene= 78.11 g/moleMolar mass of cyclohexane= 84.16 g/moleMole fractionThe molar fraction is a way of measuring the concentration that expresses the proportion in which a substance is found with respect to the total moles of the solution.
Being the molar mass and the mass in the solution of each compound, the number of moles of each compound can be calculated as:
Benzene: [tex]\frac{mass of benzene}{molar mass of benzene} =\frac{6.24 grams}{78.11 \frac{grams}{mole} } = 0.08 moles[/tex]Cyclohexane:[tex]\frac{mass of cyclohexane}{molar mass of ciclohexane} =\frac{80.74 grams}{84.16\frac{grams}{mole} } = 0.96 moles[/tex]So, the total moles of the solution can be calculated as:
Total moles = 0.08 moles + 0.96 moles = 1.04 moles
Finally, the mole fraction of benzene can be calculated as follow:
[tex]\frac{number moles of benzene}{total moles} =\frac{0.08 moles}{1.04 moles} = 0.077[/tex]
Finally, the mole fraction of benzene is 0.077.
MolalityMolality is the ratio of the number of moles of any dissolved solute to kilograms of solvent.
The Molality of a solution is determined by the expression:
[tex]Molality=\frac{number of moles of solute}{kilograms of solvent}[/tex]
In this case, you know:
number of moles of solute= 0.08 moles Mass of solvent = 80.74 g = 0.08074 kg (being 1000 g=1 kg)Replacing:
[tex]Molality benzene=\frac{0.08 moles}{0.08074 kg}[/tex]
Molality benzene= 0.9908 [tex]\frac{moles}{kg}[/tex]
Finally, the molality of benzene is 0.9908 [tex]\frac{moles}{kg}[/tex].
Learn more about:
mole fraction brainly.com/question/14434096?referrer=searchResults brainly.com/question/10095502?referrer=searchResults molality brainly.com/question/20366625?referrer=searchResults brainly.com/question/4580605?referrer=searchResults
Identify the following substances:
(1) An acidic gas which gives dense white fumes with NH3
(11 An alkane which can also be called a green house gas.
(iii) A solid which when kept in the open, forms a solution after som
(iv) An alloy used in electrical fittings.
(v) A metal which gives hydrogen gas on reacting with both dilute a
Write equations for the following reactions:
Aluminium oxide and Sodium hydroxide.
(ii) Zine and dilute sulphuric acid.
(
11
Answer:
1) HCl (Hydrochloric acid reacts with NH3 and forms dense fumes)
2) Methane (It is from the group of alkanes and is a green house gas)
3) Deliquescent substance (It is a solid which when kept in open forms a solution after sometime)
4) Brass (It is a solid-in-solid solution used to make electrical fittings)
5) Aluminium
Question 2:
1) Al₂O₃ + 2NaOH ⇒ 2NaAlO₂ (Sodium Aluminate) + H₂O
2) Zn + H₂SO₄ (dilute) => ZnSO₄ (Zinc Sulphate) + H₂
Answer:
HCl is the gasmethanedeliquescent substances (they absorbs water out of the air until they dissolve themselves into liquid solutions. )brassequations
Aluminium oxide and Sodium hydroxide react to form water and sodium aluminate
Al2O3 + 2NaOH → 2NaAlO2 + H2OZinc reacts with dilute sulphuric acid to form zinc sulphate and hydrogen gas
Zn + H2SO4 → ZnSO4 +H2
Determine the radius of an Al atom (in pm) if the density of aluminum is 2.71 g/cm3 . Aluminum crystallizes in a face centered cubic structure with an edge leng
Answer:
143pm is the radius of an Al atom
Explanation:
In a face centered cubic structure, FCC, there are 4 atoms per unit cell.
First, you need to obtain the mass of an unit cell using molar mass of Aluminium and thus, obtain edge length and knowing Edge = √8R you can find the radius, R, of an Al atom.
Mass of an unit cell
As 1 mole of Al weighs 26.98g. 4 atoms of Al weigh:
4 atoms × (1mole / 6.022x10²³atoms) × (26.98g / mole) = 1.792x10⁻²²g
Edge length
As density of aluminium is 2.71g/cm³, the volume of an unit cell is:
1.792x10⁻²²g × (1cm³ / 2.71g) = 6.613x10⁻²³cm³
And the length of an edge of the cell is:
∛6.613x10⁻²³cm³ = 4.044x10⁻⁸cm = 4.044x10⁻¹⁰m
Radius:
As in FCC structure, Edge = √8 R, radius of an atom of Al is:
4.044x10⁻¹⁰m = √8 R
1.430x10⁻¹⁰m = R.
In pm:
1.430x10⁻¹⁰m ₓ (1x10¹²pm / 1m) =
143pm is the radius of an Al atomThe radius of the atom of Al in the FCC structure has been 143 pm.
The FCC lattice has been contributed with atoms at the edge of the cubic structure.
The FCC has consisted of 4 atoms in a lattice.
The mass of the unit cell of Al can be calculated as:[tex]\rm 6.023\;\times\;10^2^3[/tex] atoms = 1 mole
4 atoms = [tex]\rm \dfrac{4}{6.023\;\times\;10^2^3}[/tex] moles
The mass of 1 mole Al has been 26.98 g/mol.
The mass of [tex]\rm \dfrac{4}{6.023\;\times\;10^2^3}[/tex] moles = [tex]\rm \dfrac{4}{6.023\;\times\;10^2^3}[/tex] moles × 26.98 g
The mass of 1 unit cell of Al has been = 1.792 [tex]\rm \bold{\times\;10^-^2^2}[/tex] g.
The volume of the Al cell can be calculated as:Density = [tex]\rm \dfrac{mass}{volume}[/tex]
Volume = Density × Mass
The volume of Al unit cell = 2.71 g/[tex]\rm cm^3[/tex] × 1.792 [tex]\rm \times\;10^-^2^2[/tex] g
The volume of Al cell = 6.613 [tex]\rm \times\;10^-^2^3[/tex] [tex]\rm cm^3[/tex]
The volume of the cube has been given as:Volume = [tex]\rm edge\;length^3[/tex]
6.613 [tex]\rm \times\;10^-^2^3[/tex] [tex]\rm cm^3[/tex] = [tex]\rm edge\;length^3[/tex]
Edge length = [tex]\rm \sqrt[3]{6.613\;\times\;10^-^2^3}[/tex] cm
Edge length = 4.044 [tex]\rm \times\;10^-^8[/tex] cm
Edge length = 4.044 [tex]\rm \bold{\times\;10^-^1^0}[/tex] m.
In an FCC lattice structure, the radius of the atom can be given by:Edge length = [tex]\rm \sqrt{8\;\times\;radius}[/tex]
4.044 [tex]\rm \bold{\times\;10^-^1^0}[/tex] m = [tex]\rm \sqrt{8\;\times\;radius}[/tex]
Radius = 1.430 [tex]\rm \bold{\times\;10^-^1^0}[/tex] m.
1 m = [tex]\rm 10^1^2[/tex] pm
1.430 [tex]\rm \bold{\times\;10^-^1^0}[/tex] m = 143 pm.
The radius of the atom of Al in the FCC structure has been 143 pm.
For more information about the FCC structure, refer to the link:
https://brainly.com/question/14934549
Which element has 4 valence electrons in the 3p sublevel?
The Periodic Table
A. Ga
B. Si
C. N
D. S
Answer:
D . Sulphur
Explanation:
the element with a 3p4 valence configuration, look in period 3 and group XVI, and that is ...
S, sulfur.
How does the carbon calculator estimate the amount of CO2 that each individual releases into the atmosphere?
Answer:
The calculator add the CO2 released from the use of electricity, released from driving and the CO2 from the waste that we disposed.
Explanation:
The carbon dioxide, CO2 is what the human body does not need, therefore, we breathe it out, hence taking in oxygen(respiration process). The plants need oxygen for the production of their own food.
The carbon calculator estimate the amount of CO2 that each individual releases into the atmosphere through the consideration of several factors such as the kind of food that we eat.
Therefore, if we are to use the carbon calculator to determine the amount of CO2 that each individual releases into the atmosphere we will have:
The amount of CO2 that each individual releases into the atmosphere =( CO2 released from the use of electricity) + (CO2 released from driving) + (the CO2 from the waste that we disposed).
Classify each molecule by whether its real bond angles are the same as or different than its model (ideal) bond angles. In other words, do the bond angles change when you switch between Real and Model mode at the top of the page?
The question is incomplete; the complete question is: Classify each molecule by whether its real bond angles are the same as or different than its model (ideal) bond angles. In other words, do the bond angles change when you switch between Real and Model mode at the top of the page? Same (angles do not change) Different (angles change) Answer Bank | H2O | CO2, SO2, XeF2, BF3 CIF3, NH3, CH4, SF4, XeF4, BrF5, PCI5,SF6
Answer:
Compounds whose real bond angle are the same as ideal bond angle;
SF6, BF3, CH4, PCI5
Compounds whose real bond angles differ from ideal bond angles;
H2O, CO2, SO2, XeF2, CIF3, NH3, SF4, XeF4, BrF5
Explanation:
According to the valence shell electron pair repulsion theory (VSEPR), molecules adopt various shapes based on the number of electron pairs on the valence shell of the central atom of the molecule. The electron pairs usually orient themselves as far apart in space as possible leading to various observed bond angles.
The extent of repulsion of lone pairs is greater than that of bond pairs. Hence, the presence of lone pairs on the valence shell of the central atom in the molecule distorts the bond angles of molecules away from the ideal bond angles predicted on the basis of valence shell electron pair repulsion theory.
For instance, methane is a perfect tetrahedron having an ideal bond angle of 109°28'. Both methane and ammonia are based on a tetrahedron, however, the presence of a lone pair of electrons on nitrogen distorts the bond angle of ammonia to about 107°. The distortion of lone pairs in water is even more as the bond angles of water is about 104°.
If you combine 24.2 g of a solute that has a molar mass of 24.2 g/mol with 100.0 g of a solvent, what is the molality of the resulting solution
Answer: 10 moles/kg.
Explanation:
Given, Mass of solute = 24.2 g
Molar mass of solute = 24.2 g/mol
[tex]\text{Moles of solute =}\dfrac{\text{Mass of solute}}{\text{Molar mass of solute}}\\\\=\dfrac{24.2}{24.2}=1[/tex]
Mass of solvent = 100.0g = 0.1 kg [1 g=0.001 kg]
[tex]\text{Molality}=\dfrac{\text{Moles of solute}}{\text{kilograms of Solvent}}\\\\=\dfrac{1}{0.1}\\\\=10\ moles/kg[/tex]
Hence, the molality of the resulting solution is 10 moles/kg.
What is the freezing point of an aqueous solution that boils at 105.9 ∘C? Express your answer using two significant figures.
Answer:
THE FREEZING POINT OF THE AQUEOUS SOLUTION IS - 7.3 °C
Explanation:
To solve this problem, we must know the following variables:
Normal boiling point of water (solvent) = 100 °C
The molar boiling point elevation constant of water = 1.51 °C /m
Normla freezing point of water ( solvent) = 0 °C
The molar freezing point depression constant = 1.86 °C /m
The boiling point of the aqueous solution = 105.9 °C
Molarity = xM
Change in boiling point = boiling point of solution - boiling point of water
Change in boiling point = 105.9 - 100 °C
= 5.9 °C
From the formula:
Change in boiling point = i * Kb * M
Re- arranging the formula by making M the subject of the equation, we have:
M = change in boiling point / Kb
i = 1
M = 5.9 °C / 1.51 °C/m
M = 3.907 M
Then, we calculate the freezing point:
Change in freezing point = i * Kb * M
= 1 * 1.86 °C/m * 3.907 M
= 7.267 °C
Hence, the freezing point = freezing point of water - change in freezing point
Freezing point = 0 °C - 7.267 °C
Freezing point = - 7.267 °C
Freezing point = -7.3 °C
g The most common position for an double bond in an unsaturated fatty acid is delta _________(fill in the number).
Answer:
The most common position for an double bond in an unsaturated fatty acid is delta 9 (Δ⁹)
Explanation:
Unsaturated fatty acids are carboxylic acids which contains one or more double bonds. The chain length as well as the number of double bonds is written separated by a colon. The positions of the double bonds are specified starting from the carboxyl carbon, numbered as 1, by superscript numbers following a delta (Δ). For example, an 18-carbon fatty acid containing a single double bond between carbon number 9 and 10 is written as 18:1(Δ⁹).
In most monounsaturated fatty acids, the double bond is between C-9 and C-10 (Δ⁹), and the other double bonds of polyunsaturated fatty acids are generally Δ¹² and Δ¹⁵. This positioning is due to the nature of the biosynthesis of fatty acids. In the mammalian hepatocytes, double bonds are introduced easily into fatty acids at the Δ⁹ position, but cannot introduce additional double bonds between C-10 and the methyl-terminal end. However, plants are able to introduce these additional double bonds at the Δ¹² and Δ¹⁵ positions.
Which best describes the trends in electonegativity on the periodic table
Hey! :)
__________ ☆ ☆__________________________________
Answer:
The answer is Electronegativity increases up and to the right
Explanation:
When you move from left to right it increases ( in the periodic table )
But when you move down the table electronegativity decreases.
So “ Electronegativity increases up and to the right” describes the trends the best.
Hope this helps! :)
____________☆ ☆________________________________
By, BrainlyMember ^-^
Good luck!
Calculate the percent ionization of nitrous acid in a solution that is 0.249 M in nitrous acid. The acid dissociation constant of nitrous acid is
Answer:
4.26 %
Explanation:
There is some info missing. I think this is the original question.
Calculate the percent ionization of nitrous acid in a solution that is 0.249 M in nitrous acid. The acid dissociation constant of nitrous acid is 4.50 × 10 ⁻⁴.
Step 1: Given data
Initial concentration of the acid (Ca): 0.249 M
Acid dissociation constant (Ka): 4.50 × 10 ⁻⁴
Step 2: Write the ionization reaction for nitrous acid
HNO₂(aq) ⇒ H⁺(aq) + NO₂⁻(aq)
Step 3: Calculate the concentration of nitrite in the equilibrium ([A⁻])
We will use the following expression.
[tex][A^{-} ] = \sqrt{Ca \times Ka } = \sqrt{0.249 \times 4.50 \times 10^{-4} } = 0.0106 M[/tex]
Step 4: Calculate the percent ionization of nitrous acid
We will use the following expression.
[tex]\alpha = \frac{[A^{-} ]}{[HA]} \times 100\% = \frac{0.0106M}{0.249} \times 100\% = 4.26\%[/tex]
why Al is a member of group 13 rather than group 3?
Answer:
Boron and Aluminium
Explanation:
Boron and Aluminium are present in Group 13 of the modern periodic table. Group 13 (IUPAC System) can also be referred to as Group III-A. Logically, Boron and Aluminum can't be placed alongwith elements such as Yttrium as they don't exhibit properties of a transition metal.
Question 4 (2 points)
CuO(s) + H2(g)
Cu(s) +
H2O(1)
Balance the equation
Answer:
CuO(s) + H₂(g) --> Cu(s) + H₂O(l)
Explanation:
It is already balanced. You can see that the values of the elements of the reactants are equal to the values of the elements of the products.
An electrode has a negative electrode potential. Which statement is correct regarding the potential energy of an electron at this electrode?
A. An electron at this electrode has the same potential energy as it has at a standard hydrogen electrode.
B. An electron at this electrode has a lower potential energy than it has at a standard hydrogen electrode.
C. An electron at this electrode has a higher potential energy than it has at a standard hydrogen electrode.
Answer:
C. An electron at this electrode has a higher potential energy than it has at a standard hydrogen electrode.
Explanation:
The standard hydrogen electrode (SHE) is used to measure the electrode potential of substances. The standard hydrogen electrode is arbitrarily assigned an electrode potential of zero. Recall that electrode potentials are always measured as reduction potentials in electrochemical systems.
For an electrode that has a negative electrode potential, electrons at this electrode have a higher potential energy compared to electrons at the standard hydrogen electrode. Electrons flow from this electrode to the hydrogen electrode.
On the other hand, a positive electrode potential implies that an electron at this electrode has a lower potential energy than it has at a standard hydrogen electrode. Hence electrons will flow from the standard hydrogen electrode to this electrode.
A sample of a pure compound that weighs 60.3 g contains 20.7 g Sb (antimony) and 39.6 g F (fluorine). What is the percent composition of fluorine
Answer:
The percent composition of fluorine is 65.67%
Explanation:
Percent Composition is a measure of the amount of mass an element occupies in a compound. It is measured in percentage of mass.
That is, the percentage composition is the percentage by mass of each of the elements present in a compound.
The calculation of the percentage composition of an element is made by:
[tex]percent composition element A=\frac{total mass of element A}{mass of compound} *100[/tex]
In this case, the percent composition of fluorine is:
[tex]percent composition of fluorine=\frac{39.6 g}{60.3 g} *100[/tex]
percent composition of fluorine= 65.67%
The percent composition of fluorine is 65.67%
Answer:
The percent composition of fluorine is 65.67%
Explanation:
Percent Composition is a measure of the amount of mass an element occupies in a compound. It is measured in percentage of mass.
That is, the percentage composition is the percentage by mass of each of the elements present in a compound.
The calculation of the percentage composition of an element is made by:
In this case, the percent composition of fluorine is:
percent composition of fluorine= 65.67%
The percent composition of fluorine is 65.67%
Using the provided table, determine the enthalpy for the reaction
2 NH3 (g) + 3 N20 (g) 4 N2 (g) + 3 H20 (1)
Answer:
ΔH°r = -1009.8 kJ
Explanation:
Let's consider the following balanced reaction.
2 NH₃(g) + 3 N₂O(g) ⇒ 4 N₂(g) + 3 H₂O(l)
We can calculate the standard enthalpy of the reaction (ΔH°r) using the following expression.
ΔH°r = [4 mol × ΔH°f(N₂(g)) + 3 mol × ΔH°f(H₂O(l))] - [2 mol × ΔH°f(NH₃(g)) + 3 mol × ΔH°f(N₂O(g))]
ΔH°r = [4 mol × 0 kJ/mol + 3 mol × (-285.8 kJ/mol)] - [2 mol × (-46.2 kJ/mol) + 3 mol × 81.6 kJ/mol]
ΔH°r = -1009.8 kJ