Answer:
The answer is B
Explanation:
Answer:
B. Learning about the physical world through observation
Explanation:
A p e x 2021 :) Trust me!
What is the name of CaCl2 7H2o
Answer:
calcium chloride dihydrate
"The pH of a solution of household ammonia, a 0.950-M solution of NH3, is 11.612. What is Kb" for NH3
Answer:
Kb = 1.77x10⁻⁵
Explanation:
When NH₃, a weak base, is in equilibrium with waterm the reaction that occurs is:
NH₃(aq) + H₂O(l) ⇄ NH₄⁺(aq) + OH⁻(aq)
And the dissociation constant, Kb, for this equilibrium is:
Kb = [NH₄⁺] [OH⁻] / [NH₃]
To find Kb you need to find the concentration of each species. The equilibrium concentrations are:
[NH₃] = 0.950M - X
[NH₄⁺] = X
[OH⁻] = X
Where X is reaction coordinate.
You can know [OH⁻] and, therefore, X, with pH of the solution, thus:
pH = -log [H⁺] = 11.612
[H⁺] = 2.4434x10⁻¹²
As 1x10⁻¹⁴ = [H⁺] [OH⁻]
1x10⁻¹⁴ / 2.4434x10⁻¹² = [OH⁻]
4.0926x10⁻³ = [OH⁻] = X
Replacing, concentrations of the species are:
[NH₃] = 0.950M - X
[NH₄⁺] = X
[OH⁻] = X
[NH₃] = 0.9459M
[NH₄⁺] = 4.0926x10⁻³M
[OH⁻] = 4.0926x10⁻³M
Replacing in Kb expression:
Kb = [NH₄⁺] [OH⁻] / [NH₃]
Kb = [4.0926x10⁻³M] [4.0926x10⁻³M] / [0.9459M]
Kb = 1.77x10⁻⁵The branch of science which deals with the chemical bond is called Chemistry.
The correct answer to the question is [tex]Kb = 1.77*10^{-5[/tex]
Explanation:
When NH₃, is acts as a weak base it forms an equilibrium with water the reaction occurs is:
[tex]NH_3(aq) + H_2O(l) ---><NH_4^+(aq) + OH^-(aq)[/tex]
The formula we gonna use is as follows:-
[tex]Kb = \frac{[NH_4^+] [OH^-]}{[NH_3]}[/tex]
The data is given in the question is as follows:-
[NH₃] = 0.950M - X [NH₄⁺] = X [OH⁻] = X
Where X stands for reaction coordinate.
After solving the ph of the compound the value is as follows:-
[NH₃] = [tex]0.9459M[/tex] [NH₄⁺] = [tex]4.0926*10^{-3}M[/tex] [OH⁻] = [tex]4.0926*10^{-3}M[/tex]
Putting the value in the formula.
[tex]Kb = \frac{[4.0926*10^{-3}M] [4.0926*10^{-3}M]}{[0.9459M]}[/tex]
After solving the equation the value of Kb is [tex]1.77*10^{-5[/tex]
Hence, the correct answer is [tex]1.77*10^{-5[/tex]
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Consider the addition of an electron to the following atoms from the fourth period. Rank the atoms in order from the most negative to the least negative electron affinity values based on their electron configurations.
Atom or ion Electron configuration
Br 1s22s22p63s23p64s23d104p5
Ge 1s22s22p63s23p64s23d104p2
Kr 1s22s22p63s23p64s23d104p6
Answer:
Ge: [Ar] 3d10 4s2 4p2 => 6 electrons in the outer shell
Br: [Ar] 3d10 4s2 4p5 => 7 electrons in the outer shell
Kr: [Ar] 3d10 4s2 4p6 => 8 electrons in the outer shell
Explanation:
The electron affinity or propension to attract electrons is given by the electronic configuration. Remember that the most stable configuration is that were the last shell is full, i.e. it has 8 electrons.
The closer an atom is to reach the 8 electrons in the outer shell the bigger the electron affinity.
Of the three elements, Br needs only 1 electron to have 8 electrons in the outer shell, so it has the biggest electron affinity (the least negative).
Ge: needs 2 electrons to have 8 electrons in the outer shell, so it has a smaller (more negative) electron affinity than Br.
Kr, which is a noble gas, has 8 electrons and is not willing to attract more electrons at all, the it has the lowest (more negative) electron affinity of all three to the extension that really the ion is so unstable that it does not make sense to talk about a number for the electron affinity of this atom.
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An atom of element number 33 (As) is in its ground electronic state. Which one of the following sets quantum numbers could not apply to any of its electrons?
A) n=2 l=1 ml= -1 ms= 1/2
B) n=3 l=0 ml=0 ms= -1/2
C) n=3 l=2 ml=-2 ms= -1/2
D) n=4 l=0 ml=0 ms= -1/2
E) n=4 l=2 ml=1 ms= 1/2
Answer:
E) n=4 l=2 ml=1 ms= 1/2
Explanation:
Arsenic is a member of group 15 in the periodic table. Its electronic configuration is;
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p3. Its condensed electronic configuration can be written as [Ar]4s2 3d10 4p3. This electronic configuration shown here can now enable us to consider each option given in the question in order to meaningfully arrive at a logical answer.
If we look at option E, the data given for that electron is; n=4 l=2 ml=1 ms= 1/2. This refers to an electron in a 4d orbital. In the ground state configuration of arsenic shown above, there is no 4d orbital, hence option E must be the correct answer.
Use standard reduction potentials to calculate the equilibrium constant for the reaction: 2Cr3+(aq) + Pb(s)2Cr2+(aq) + Pb2+(aq) Hint: Carry at least 5 significant figures during intermediate calculations to avoid round off error when taking the antilogarithm. Equilibrium constant: G° for this reaction would be _________ than zero. Submit AnswerRetry Entire Group
Answer:
3.47 ×10^-10
Explanation:
The equation of the reaction is 2Cr3+(aq) + Pb(s)------->2Cr2+(aq) + Pb2+(aq)
A total of two moles of electrons were transferred in the process. The chromium was reduced while the lead was oxidized. Hence the lead species will constitute the oxidation half equation and the chromium will constitute the reduction half equation.
E°cell = E°cathode - E°anode
E°cathode = -0.41 V
E°anode = -0.13 V
E°cell = -0.41 -(-0.13) = -0.28 V
From
E°cell = 0.0592/n log K
n= 2, K= the unknown
-0.28 = 0.0592/2 log K
log K = -0.28/0.0296
log K = -9.4595
K = Antilog ( -9.4595)
K= 3.47 ×10^-10
Which land feature supports the theory of continental drift?
A.canyons B.volcanoes C.coal fields D.oceans
Answer:
Coals
Explanation:
The land feature that supports the theory of continental drift is ; ( C ) coal fields
Continental drift is the gradual shift in position of the earth tectonic plates ( i.e. gradual shift in the continents in relation to ocean basins) and this due to the heat from the earths' mantle.
Coal fields supports this theory because the it is an area where coal is found in large quantities and mined for commercial purposes. coal fields areas are found as a result of continental drift.
Hence we can conclude that the land feature that supports the theory of continental drift is coal fields
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Think about what you know about science today. How do you think scientific knowledge will be different in 100 years?
Answer:
I think we will know a lot more about the universe and the things around us. We may also know a lot more about other planets, such as Mars and Saturn, and we might also know a lot more about other stars in the universe.
Explanation:
A student mixed 115 g of sugar, 350 g of water and 5 g of spices. What will be the mass of the solution?
these are the options
470g
465g
350g
120g
Answer:
[tex]m_{solution}=470g[/tex]
Explanation:
Hello,
In this case, a solution is formed when a solute is completely dissolved in a solvent, thus, for this situation, the sugar is the solute and the water the solvent but in addition to them we find spices which are also considered in the total mass of the solution. In such a way, for computing the total mass we must add the mass of three constituents (115 g sugar, 350 g water and 5 g spices) as shown below:
[tex]m_{solution}=115g+350g+5g\\\\m_{solution}=470g[/tex]
Best regards.
A correct name for the following compound is:_________.a) 4-bromo-3,8-dimethylbicyclo[5.2.2]nonane b) 3,8-dimethyl-4-bromo-bicyclo[5.2.O)nonane c) 4-bromo-3,8-dimethylbicyclo[5.2.1]decane d) 7-bromo-2,6-dimethylbicyclo[5.2.0]nonane e) 4-bromo-3,8-dimethylbicyclo[5.2.0]nonane
Answer:
e) 4-bromo-3,8-dimethylbicyclo[5.2.0]nonane
Explanation:
The missing image of the the compound we are to name is attached below.
Before we can name an organic compound; It is crucial we know the guiding rules in naming them.
1. Select the longest continuous carbon chain as the root hydrocarbon and name according to the number of carbon atoms it contains, adding appropriate suffix to indicate the principal substituent group.
2. Number the carbon atoms in the root hydrocarbon from the end which gives the lowest number to the substituents.
3. If the same substituent is present two or more times in a molecule; the number of this substituent is indicated by the prefix di -(2), tri - (3) , tetra - (4) etc attached to the substituent name.
4. If there is more than one type of substituent in the molecule ; the substituents are named according to the alphabetical order but where there are mixed substituents ; the inorganic are named first.
5. In selecting and numbering the longest continuous chain, the functional groups are given preference over substituents., i.e the functional group is given the smallest possible number.
In the light of the above guiding rules; we were able to name the given compound because the compound contains nine carbons in the ring form which result to root name nonane. The two methyl are on the third and eight carbon; bromine is on the fourth carbon ; there are two cyclic ring present in the compound where we have 5 carbons in one structure, another 2 carbons in the second structure and zero carbon in the bridge structure which eventually result to the correct name:
4-bromo-3,8-dimethylbicyclo[5.2.0]nonane
Why can liquids change shape but solids cannot
Answer:
Explanation:
the forces between the molecules are stronger in solid than in liquids
Based on the properties of the compounds in the interactive, predict whether the given compounds behave as electrolytes or as nonelectrolytes.
1. LioH
2. C4H2O4
3. LiBr
4. HNo3
Explanation:
Before proceeding we have to understand what electrolytes and non electrolytes are;
An electrolyte is a substance that produces an electrically conducting solution when dissolved. An electrolyte is a compound that can dissociate into ions.
Non electrolytes: A substance whose molecules in solution do not dissociate to ions and thus do not conduct an electric current
Going through the options;
1. LiOH
This is a compound of hat would dissociate into Li+ and OH-. This is an electrolyte.
2. C4H2O4
This is an organic compound. Gnerally organic acids are non electrolytes, with the exception og the acids. This is a nonelectrolyte.
3. LiBr
This is an electrolyte because it would dissociate into Li+ and Br- ions.
4. HNO3
HNO3 is a strong acid. Because it is a strong acid it will dissociate completely into its ions (H+ and NO3-). Therefore we consider HNO3 to be a strong electrolyte.
A chemistry student weighs out of hypochlorous acid into a volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with solution. Calculate the volume of solution the student will need to add to reach the equivalence point. Round your answer to significant digits.
Answer:
Volume of NaOH, aka V2 = 6.32 mL to 3 sig. fig.
A chemistry student weighs out 0.0941 g of hypochlorous acid (HClo) into a 250. ml. volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with 0.2000 M NaOH solution. Calculate the volume of NaOH solution the student will need to add to reach the equivalence point. Round your answer to 3 significant digits mL.
Explanation:
1 mole HClO = 74.44g
0.0941g = [tex]\frac{0.0941}{74.44}[/tex] = 0.00126 moles
Concentration = no. of moles/volume in L
Hence, Concentration of HClO = 0.00126/ 0.250L
= 0.005M.
C1V1 =C2V2
0.005 × 250 mL = 0.2 × V2
Volume of NaOH, aka V2 = 6.32 mL to 3 sig. fig.
Write a net ionic equation to show that benzoic acid, C6H5COOH, behaves as a Brønsted-Lowry acid in water.
Answer:
H⁺(aq) + H₂O(l) ⇄ H₃O⁺(aq)
Explanation:
According to Brönsted-Lowry acid-base theory, an acid is a substance that donates H⁺. Let's consider the molecular equation showing that benzoic acid is a Brönsted-Lowry acid.
C₆H₅COOH(aq) + H₂O(l) ⇄ C₆H₅COO⁻(aq) + H₃O⁺(aq)
The complete ionic equation includes all the ions and molecular species.
C₆H₅COO⁻(aq) + H⁺(aq) + H₂O(l) ⇄ C₆H₅COO⁻(aq) + H₃O⁺(aq)
The net ionic equation includes only the ions that participate in the reaction and the molecular species.
H⁺(aq) + H₂O(l) ⇄ H₃O⁺(aq)
For the reaction of nitrogen gas and hydrogen gas to make methane, describe FOUR stresses that would shift the equilibrium to the left toward the reactants? N2(g) + 3 H2(g) ⇌ 2 NH3(g) + Energy
Answer:
- Addition of NH₃(g)
- Removal of N₂(g)
- Increase of temperature
- Pressure decrease
Explanation:
According to Le Chatelier's principle, if we apply an stress to a reaction at equilibrium, the system will try to shift the equilibrium in order to decrease the stress. If we add reactants, the equilibrium will shift toward the formation of more products (to the consumption of reactants) and vice versa.
The stresses we can apply to this equilibrium are the following:
- Addition of NH₃(g) : it is a product, thus its addition will result in a shift toward reactants.
- Removal of N₂(g): it is a reactant, thus its removal from the reaction mixture will result in a shift toward reactants.
- Increase of temperature: the reaction is exothermic, so it releases energy. Energy is a product. If we add energy (increase the temperature), we are adding a product, so the equilibrium will shift toward the reactants.
- Pressure decrease: because both reactants and products are in the gas phase. A decrease in pressure shifts an equilibrium to the side of the reaction with greater number of moles of gas. In this case, the reactants side has greater number of moles of gas (1 mol + 3 moles= 4 moles) than the products side (2 moles). Thus, the equilibrum will shift toward reactants.
The reduction of iron(III) oxide to iron metal is an endothermic process: Fe2O3(s) + 2 CO(g) → 2 Fe(s) + 3 CO2(g) ΔH = +26.3 kJ How many kilojoules of energy are required to produce 1.00 kilogram of iron metal?
Answer: Thus 234 kJ of energy are required to produce 1.00 kilogram of iron metal
Explanation:
To calculate the number of moles , we use the equation:
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
Putting values , we get:
[tex]\text{Moles of iron}=\frac{1000g}{56g/mol}=17.8moles[/tex] (1.00kg=1000g)
The balanced chemical reaction is:
[tex]Fe_2O_3(s)+2CO(g)\rightarrow 2Fe(s)+3CO_2(g)[/tex] [tex]\Delta H=+26.3kJ[/tex]
Given :
Energy released when 2 moles of [tex]Fe[/tex] is produced = 26.3 kJ
Thus Energy released when 17.8 moles of [tex]Fe[/tex] is produced =
= [tex]\frac{26.3kJ}{2}\times 17.8=234kJ[/tex]
Thus 234 kJ of energy are required to produce 1.00 kilogram of iron metal
100. mLmL of 0.200 MMHClHCl is titrated with 0.250 MMNaOHNaOH. Part A What is the pH of the solution at the equivalence point? Express the pH numerically.
Answer:
pH = 7.0
Explanation:
When HCl reacts with NaOH, H₂O and NaCl are produced, thus:
HCl + NaOH → H₂O + NaCl
At equivalence point, all HCl reacts with NaOH. The only you will have is water.
Equilbrium of water is:
H₂O(l) ⇄ H⁺(aq) + OH⁻(aq)
K = 1x10⁻¹⁴ = [H⁺] [OH⁻]
As H⁺ = OH⁻ because both are produced from the same water-
1x10⁻¹⁴ = [H⁺]²
1x10⁻⁷M = [H⁺]
As pH = -log= [H⁺]
pH = 7.0-The pH at equivalence point in the titration of a strong acid with a strong base is always 7.0-
A volume of 0.800 L of a 2 x 10–4 M Ba(NO3)2 solution is added to 0.200 L of 5 x 10–4 M Li2SO4. Does BaSO4 precipitate? Explain your answer
Answer:
The BaSO₄ precipitates as a solid.
Explanation:
In order to determine the precipitation, we need to look at the reactants, we have: Ba(NO₃)₂ and Li₂SO₄
Salts from nitrate are all soluble and sulfates can make precipitate if they react to elements from group 2. (Solubility rules) So this reaction, has a precipitate but we can predict it, if we look at the reaction and we take acount the Kps:
Ba(NO₃)₂ (aq) + Li₂SO₄ (aq) → 2LiNO₃ (aq) + BaSO₄ (s) ↓
Let's find out the moles of each ion:
Ba(NO₃)₂ (aq) → Ba²⁺ (aq) + 2NO₃⁻ (aq)
0.8 L . 0.0002 M = 1.6×10⁻⁴ moles. These are the moles of Ba²⁺ in 1 L of solution, so [Ba²⁺] = 1.6×10⁻⁴ M
Li₂SO₄ (aq) → 2Li⁺ (aq) + SO₄⁻² (aq)
0.2 L . 0.0005 M = 1×10⁻⁴ M. These are the moles of sulfate, in 1 L of solution so [SO₄⁻²] = 1×10⁻⁴ M
BaSO₄ (s) ⇆ Ba²⁺ (aq) + SO₄⁻² (aq) Kps = 1.08×10⁻¹⁰
We need to compare Kps to [ Ba²⁺] . [SO₄⁻²]
[ Ba²⁺] . [SO₄⁻²] = 1.6 ×10⁻⁸ > Kps → Precipitate.
If [Ba²⁺] . [SO₄⁻²] = Kps → Solution is saturated
If [ Ba²⁺] . [SO₄⁻²] < Kps → There is no precipitate formed, or if it is formed, it will be quickly dissolved to reach saturation.
A beach has a supply of sand grains composed of calcite, ferromagnesian silicate minerals, and non-ferromagnesian silicate minerals. If it undergoes lots of chemical weathering, which sand grains will be quickly chemically weathered away?
a. Calcite
b. ferromagnesian silicate minerals
c. non-ferromagnesian silicate minerals
The sand that grained will be quickly chemically weathered away should be option b. ferromagnesian silicate minerals.
What are ferromagnesian silicate minerals?It should be considered as the Silicate minerals where cations of iron and the form of magnesium should be important for the chemical components. It is used for covering up the minerals. Also, calcite should be normal weather via the solution process so it required a lot of water that contains a high amount of carbonic acid.
Hence, the correct option is b.
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differentiate between satured and unsatured fats
Answer:
...
Explanation:
in saturated fats there is no double bond between the acids and are tightly packed and unsaturated fats arent tight and loosely packed/put together
saturated- solid at room temperature
unsaturated= liquid at room temperature
two types of unsaturated fats, Polyunsaturated fats and Monounsaturated fats
Which best describes the relationship between heat internal energy, and thermal energy?
O Internal energy is heat that flows, and heat is the part of thermal energy that can be transferred.
O Internal energy is thermal energy that flows, and thermal energy is the part of heat that can be transferred.
O Thermal energy is heat that flows, and heat is the part of internal energy that can be transferred.
O Heat is thermal energy that flows, and thermal energy is the part of internal energy that can be transferred.
Answer:
Heat is thermal energy that flows, and thermal energy is the part of internal energy that can be transferred
Explanation:
8. A 25.0 mL sample of an H2SO4 solution is titrated with a 0.186 M NaOH solution. The equivalence point is reached with 12.9 mL of base. The concentration of H2SO4 is ________ M. (Hint: write a balanced chemical equation first!)
Answer:
0.0480 M
Explanation:
The reaction is ...
H₂SO₄ + 2NaOH ⇒ Na₂SO₄ +2H₂O
That is, 2 moles of NaOH react with each mole of H₂SO₄. Then the molarity of the H₂SO₄ is ...
moles/liter = (0.186 M/2)(12.9 mL)/(25.0 mL) ≈ 0.0480 M
the iupac name of the compound
Answer:
3-Pentyn-1-ol
Explanation:
tripple bond is at 3 postion from alochol
carbon are 5 atoms so pent
yn becauese its alkyne
Elvira Walks 4 miles to the west from school and stops at the store. She then walks 3 miles south.
What is the Distance and the displacement?
Answer:
distance = 7 miles
displacement = 5 miles
Explanation:
Distance is a scalar quantity as it takes account of magnitude traveled but not the direction traveled from starting point.
The distance traveled is the sum total of distances moved
distance = 4 + 3 = 7 miles
Displacement however, is a vector and measure the shortest possible distance traveled in a given direction from the starting point.
The path of Elvis' walking forms a right-angle triangle with the hypotenuse being the displacement and the other two sides being the distance traveled west and south.
Using Pythagoras' theorem; c² = a² + b²
where c = hypotenuse and a and b are the other two sides
c² = 4² + 3²
c² = 16 + 9 = 25
√c² = √25
c = 5
Therefore, displacement = 5 miles
What is the pH of a solution prepared by dissolving 0.140 g of potassium hydroxide in sufficient pure water to prepare 250.0 ml of solution
Answer:
pH= 12
Explanation:
Potassium hydroxide (KOH) is a strong base, so it dissociates completely in water by giving OH⁻ anions as follows:
KOH⇒ K⁺ + OH⁻
Since dissociation is complete, it is assumed that the concentration of OH⁻ is equal to the initial concentration of KOH:
[OH⁻]= [KOH]
In order to find the initial concentration of KOH, we have to divide the mass (0.140 g) into the molecular weight of KOH (Mw):
Mw (KOH)= K + O + H = 39 g/mol + 16 g/mol + 1 g/mol = 56 g/mol
moles KOH: mass/Mw= 0.140 g/(56 g/mol) = 2.5 x 10⁻³ moles
The molality of the solution is the number of moles of KOH per liter of solution:
V= 250.0 ml x 1 L/1000 ml= 0.250 L
M = (2.5 x 10⁻³moles)/(0.250 L)= 0.01 M
Now, we calculate pOH:
pOH = -log [OH⁻]= - log [KOH]= -log (0.01) = 2
Finally, we calculate pH from pOH:
pH + pOH = 14
⇒pH = 14 - pOH= 14 -2 = 12
which process is used to produce gases from solutions of salts dissolved in water or another liquid?
A.Electrolysis
B.Metallic bonding
C.Ionic bonding
D. Polar covalent bonding
Answer:
A.Electrolysis
Explanation:
A.Electrolysis
For example, electrolysis of solution of NaCl in water gives H2 and O2.
Balance the chemical equation
Fe2O3 (s) + CO (g) 2 Fe(s) + CO2 (g)
Express your answer as a chemical equation. Identify all of the phases in your answer.
Answer:
[tex]Fe_2O_3+3CO\Rightarrow \:2Fe+3CO_2[/tex]
Explanation:
[tex]Fe_2O_3+CO\Rightarrow \:2Fe+CO_2\\\\Fe_2O_3+3CO\Rightarrow \:2Fe+3CO_2[/tex]
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The electron in a hydrogen atom, originally in level n = 8, undergoes a transition to a lower level by emitting a photon of wavelength 3745 nm. What is the final level of the electron?(c=3.00×10^8m/s, h=6.63×10^-34 J·s, RH=2.179×106-18J)a. 5
b. 6
c. 8
d. 9
e. 1
Explanation:
It is given that,
The electron in a hydrogen atom, originally in level n = 8, undergoes a transition to a lower level by emitting a photon of wavelength 3745 nm. It means that,
[tex]n_i=8[/tex]
[tex]\lambda=3745\ nm[/tex]
The amount of energy change during the transition is given by :
[tex]\Delta E=R_H[\dfrac{1}{n_f^2}-\dfrac{1}{n_i^2}][/tex]
And
[tex]\dfrac{hc}{\lambda}=R_H[\dfrac{1}{n_f^2}-\dfrac{1}{n_i^2}][/tex]
Plugging all the values we get :
[tex]\dfrac{6.63\times 10^{-34}\times 3\times 10^8}{3745\times 10^{-9}}=2.179\times 10^{-18}[\dfrac{1}{n_f^2}-\dfrac{1}{8^2}]\\\\\dfrac{5.31\times 10^{-20}}{2.179\times 10^{-18}}=[\dfrac{1}{n_f^2}-\dfrac{1}{8^2}]\\\\0.0243=[\dfrac{1}{n_f^2}-\dfrac{1}{64}]\\\\0.0243+\dfrac{1}{64}=\dfrac{1}{n_f^2}\\\\0.039925=\dfrac{1}{n_f^2}\\\\n_f^2=25\\\\n_f=5[/tex]
So, the final level of the electron is 5.
A 5.00g of X, the product of organic synthesis is obtained in a 1.0 dm3 aqueous solution. Calculate the mass of X that can be extracted from the aqueous solution by a 50cm3 of ethoxy ethane. (KD (X) =40.
Answer:
mass of X extracted from the aqueous solution by 50 cm³ of ethoxy ethane = 3.33 g
Explanation:
The partition coefficient of X between ethoxy ethane (ether) and water, K is given by the formula
K = concentration of X in ether/concentration of X in water
Partition coefficient, K(X) between ethoxy ethane and water = 40
Concentration of X in ether = mass(g)/volume(dm³)
Mass of X in ether = m g
Volume of ether = 50/1000 dm³ = 0.05 dm³
Concentration of X in ether = (m/0.05) g/dm³
Concentration of X in water = mass(g)/volume(dm³)
Mass of X in water left after extraction with ether = (5 - m) g
Volume of water = 1 dm³
Concentration of X in water = (5 - m/1) g/dm³
Using K = concentration of X in ether/concentration of X in water;
40 = (m/0.05)/(5 - m)
(m/0.05) = 40 × (5 - m)
(m/0.05) = 200 - 40m
m = 0.05 × (200 - 40m)
m = 10 - 2m
3m = 10
m = 10/3
m = 3.33 g of X
Therefore, mass of X extracted from the aqueous solution by 50 cm³ of ethoxy ethane = 3.33 g
c) What is the pH of the buffer system in part a when 0.030 moles of strong acid are added (without a change in volume)
Answer:
remain the same
Explanation:
The pH of the buffer system remain the same when 0.030 moles of strong acid are added because buffer system has the property to resist any change in the pH when acid or base is added to the solution. In buffer system, one molecule is responsible for neutralizing the pH of the solution by giving H+ or OH-.This molecule is known as buffer agent. If more base is added, the molecule provide H+ and when more acid is added to the solution, then the molecule add OH- to the solution.
structure and correct name for 5-octyne
Answer:
Explanation:
(R)-5-octyne-4-ol
C8H140
Correct name for 5-octyne is 3-octane.
Structure is attached below.
3-Octane:Octane is a hydrocarbon and an alkane with the chemical formula C₈H₁₈, and the condensed structural formula CH₃(CH₂)₆CH₃. Octane has many structural isomers that differ by the amount and location of branching in the carbon chain. One of these isomers, 2,2,4-trimethylpentane (commonly called iso-octane) is used as one of the standard values in the octane rating scale.
The structure for 5-octyne is given below.
Correct name for it is 3-octane.
Find more information about Octane here:
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