Answer: [tex]\Delta H^{0}=-173.72[/tex] kJ/mol
Explanation: Enthalpy Change is the amount of energy in a reaction - absorption or release - at a constant pressure. So, Standard Enthalpy of Formation is how much energy is necessary to form a substance.
The standard enthalpy of formation of HCl is calculated as:
[tex]\Delta ^{0}=\Sigma H_{products}-\Sigma H_{reactants}[/tex]
[tex]Ca(OH)_{2}_{(aq)}+2HCl_{(aq)}[/tex] → [tex]CaCl_{2}_{(s)}+2H_{2}O_{(l)}[/tex]
Standard Enthalpy of formation for the other compounds are:
Calcium Hydroxide: [tex]\Delta H^{0}=[/tex] -1002.82 kJ/mol
Calcium chloride: [tex]\Delta H^{0}=[/tex] -795.8 kJ/mol
Water: [tex]\Delta H^{0}=[/tex] -285.83 kJ/mol
Enthalpy is given per mol, which means we have to multiply by the mols in the balanced equation.
Calculating:
[tex]-17.2=[-795.8+2(285.85)]-[-1002.82+2\Delta H][/tex]
[tex]-17.2=-1367.46+1002.82-2\Delta H[/tex]
[tex]2\Delta H=17.2-364.64[/tex]
[tex]\Delta H=-173.72[/tex]
So, the standard enthalpy of formation of HCl is -173.72 kJ/mol
How to change 5 % W/V of NaCl to ppm , M ? molar mass = 58.5
please clear explain
Answer:
50000ppm and 0.855M.
Explanation:
ppm is an unit of chemistry defined as the ratio between mg of solute (NaCl) and Liters of solution. Molarity, M, is the ratio between moles of NaCl and liters
A 5% (w/v) NaCl contains 5g of NaCl in 100mL of solution.
To solve the ppm of this solution we need to find the mg of NaCl and the L of solution:
mg NaCl:
5g * (1000mg / 1g) = 5000mg
L Solution:
100mL * (1L / 1000mL) = 0.100L
ppm:
5000mg / 0.100L = 50000ppm
To find molarity we need to obtain the moles of NaCl in 5g using its molar mass:
5g * (1mol / 58.5g) = 0.0855moles NaCl
Molarity:
0.0855mol NaCl / 0.100L = 0.855M
When C2H4(g) reacts with H2O(g) to form CH3CH2OH(g) according to the following equation, energy is released into the surroundings. C2H4(g) H2O(g) CH3CH2OH(g) Is this reaction endothermic or exothermic
Answer:
Exothermic
General Formulas and Concepts:
Chemistry
Thermodynamics
Exothermic - releases heat as a productEndothermic - absorbs heat as a reactantExplanation:
We are given that the reaction takes place between C₂H₄ (g) and H₂O (g) to form CH₃CH₂OH (g) and is releasing heat.
This means that heat would be product as it is being released during the reaction.
Therefore, we have an exothermic reaction.
< Progress: 19/21 groups Due Jan 15 at 11:55 PM Use the References to access important values if needed for this question. The compound cobalt (II) sulfate forms a hydrate with seven water molecules per formula unit. What are the name and formula of the hydrate
Answer:
CoSO4.7H2O
Cobalt II tetraoxosulphate VI heptahydrate
Explanation:
According to IUPAC nomenclature, compounds are named systematically.
We were told that there are seven water molecules in each formula unit Hence the correct formula of the compound is CoSO4.7H2O
According to IUPAC system, the metal is first named, followed by its oxidation state in Roman numerals. Then the name of the anion is mentioned as well as the number of water molecules. We have to take into account the correct prefix signifying the number of molecules of water of crystallization.
The Question A 1.80 x 10-2 kg block of metal has the following dimensions: 0.4981 inches by 0.531 inches, by 0.5839 inches. Determine the density of the block in g/mL. Using the provided list of metals and their respective densities, what is the metal's identity
Answer:
Zinc
Explanation:
m = Mass of block [tex]1.8\times 10^{-2}\ \text{kg}=18\ \text{g}[/tex]
Dimension of block is 0.4981 inches by 0.531 inches, by 0.5839 inches
[tex]1\ \text{inch}^3=16.3871\ \text{mL}[/tex]
Volume of block
[tex]V=0.4981\times 0.531\times 0.5839\times 16.3871\ \text{mL}[/tex]
Density is given by
[tex]\rho=\dfrac{m}{V}\\\Rightarrow \rho=\dfrac{18}{0.4981\times 0.531\times 0.5839\times 16.3871}\\\Rightarrow \rho=7.112\ \text{g/mL}[/tex]
The density of the metal is [tex]7.112\ \text{g/mL}[/tex]. The metal here is zinc.
Assign oxidation numbers to the element in each of the following compounds. Remember an oxidation number is for one atom of the element.
a. HgO
b. Al4C3
c. CrF2
d. Fe2S3
Answer:
a. x = + 2
b. x = + 3
c. x = + 2
d. x = + 3
Explanation:
The oxidation number is a formal charge assigned to an atom present in a molecule or formula unit or ion based on some arbitrary rules.
a.
HgO
The oxidation number of Hg in HgO is:
x + (-2) = 0
x = +2
b.
Al₄C₃
The oxidation number of Al in Al₄C₃ is:
4x +(3 × -4) = 0
4x - 12 = 0
4x = +12
x = 12/4
x = +3
c. CrF₂
x + ( 2 × - 1) = 0
x - 2 = 0
x = + 2
d. Fe₂S₃
2x + ( 3 × - 2) = 0
2x + (-6) = 0
2x = 6
x = 6/2
x = +3
A student is making a glucose solution. The student is using 12.55 g of glucose (C6H1206) and a 500 mL volumetric flask. Use this information to calculate the molarity of the glucose solution.
Answer:
M = 0.138 M
Explanation:
Given data:
Mass of glucose = 12.55 g
Volume of solution = 500 mL
Molarity of solution = ?
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
Number of moles of glucose:
Number of moles = mass/molar mass
Number of moles = 12.55 g/ 180.156 g/mol
Number of moles = 0.069 mol
Volume in L:
500 mL × 1 L /1000 mL
0.5 L
Molarity:
M = 0.069 mol / 0.5 L
M = 0.138 M
Classify each of the compounds as an ionic compound, a covalent compound or an acid.a. BaCl2______________________d. CH4______________________b. MnO2______________________e. H2S*______________________c. H3AsO4______________________f. CH3OH
Answer:
a. BaCl2 is ionic compound.
b. CH4 is covalent compound.
b. MnO2 is ionic compound.
e. H2S is covalent compound.
c. H3AsO4 is ionic compound.
f. CH3OH is covalent compound.
Explanation:
BaCl2, MnO2 and H3AsO4 are ionic compounds due to the presence of ionic bond between the atoms while on the other hand, CH4, H2S and CH3OH are covalent compounds due to the presence of covalent bond between their atoms. In covalent bonds, sharing of electrons occur whereas in ionic bonds, complete transfer of electrons occur from one atom to another atom.
If you have a gas sample with a pressure of 2 atm, a volume of 40 L and a temperature of 300 K, what will be the number of moles of gas in that sample?
Answer:
n = 3.25 mol
Explanation:
Given data:
Pressure of sample = 2 atm
Volume of sample = 40 L
Temperature = 300 K
Number of moles = ?
Solution:
PV = nRT
R = general gas constant = 0.0821 atm.L/mol.K
2 atm ×40 L = n × 0.0821 atm.L/mol.K × 300 K
80 atm.L = n × 24.63 atm.L/mol
n = 80 atm.L /24.63 atm.L/mol
n = 3.25 mol
Decide whether the compound is ionic or molecular, if you can.
Compound is a soft waxy white solid that can be easily shaped and molded by hand. When the flame of an ordinary laboratory burner is held about away from the solid, it rapidly and extensively melts into a clear liquid.
Answer:
Molecular solid
Explanation:
Molecular solids have a very low melting point. This is because, they are composed of weak intermolecular forces hence the layers of the solid easily fall apart as the solid melts.
We can see here that the solid being considered melts easily. Hence we can conclude that it is actually a molecular solid.
Which constants would most likely be filled in the first row of the table?
O temperature and moles of gas
O volume and temperature
O
pressure and volume
pressure and moles of gas
Answer:
A
Explanation:
Correct on edge
The temperature and moles of gas constants would most likely be filled in the first row of the table. Therefore, option A is correct.
What is gas constant ?The gas constant, denoted by R, is a physical constant that is expressed in terms of units of energy per temperature increment per mole. It's also referred to as the ideal gas constant, the molar gas constant, or the universal gas constant.
A general constant in the equation of state of gases that is equal to the product of the pressure and volume of one mole divided by the absolute temperature in the case of an ideal gas see gas law sense c.
All gases adapt an equation of state known as the ideal gas law: PV = nRT, where n is the number of moles of the gas and R is the universal gas constant.
Thus, option A is correct.
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Your question is incomplete, most probably your question was
The incomplete table below shows selected characteristics of gas laws.
Name
Variables
Constants
Equation
?
?
?
PV = k
Charles's law
?
?
V = kT
?
Temperature, pressure
?
P = kT
Combined gas law
Pressure, temperature, volume
?
?
Which constants would most likely be filled in the first row of the table?
temperature and moles of gas
volume and temperature
pressure and volume
pressure and moles of gas
An irregularly-shaped piece of aluminum (Al) has a mass of 66.0 grams. What is the volume in cm³ of this piece of aluminum if its density is 2.70 g/cm³?
Answer:
[tex]V=24.45\ \text{cm}^3[/tex]
Explanation:
Given that,
Mass of a piece of Aluminium, m = 66 grams
The density of Aluminium, d = 2.70 g/cm³
We need to find the volume of this piece in cm³.
We know that,
Density = mass per unit volume
[tex]d=\dfrac{m}{V}\\\\V=\dfrac{m}{d}\\\\V=\dfrac{66\ g}{2.7\ g/cm^3}\\\\V=24.45\ \text{cm}^3[/tex]
So, the volume of the piece is [tex]24.45\ \text{cm}^3[/tex].
Can anybody answer this question of chemistry?
Answer:
Answer:A
Answer:AExplanation:
Answer:AExplanation:Molar Mass of glucose = (6×12)+(1×12)+(16×6)= 180g/mol
= 180g/molNumber of moles of Glucose = Mass/Molar Mass
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180= 27.7778moles
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180= 27.7778molesIn the balanced equation of fermentation, the ratio of glucose to ethanol is 2:1
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180= 27.7778molesIn the balanced equation of fermentation, the ratio of glucose to ethanol is 2:1Therefore the number of moles of ethanol is 2×27.7778
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180= 27.7778molesIn the balanced equation of fermentation, the ratio of glucose to ethanol is 2:1Therefore the number of moles of ethanol is 2×27.7778=55.5556moles
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180= 27.7778molesIn the balanced equation of fermentation, the ratio of glucose to ethanol is 2:1Therefore the number of moles of ethanol is 2×27.7778=55.5556molesMass of ethanol= Molar Mass of ethanol × Number of moles
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180= 27.7778molesIn the balanced equation of fermentation, the ratio of glucose to ethanol is 2:1Therefore the number of moles of ethanol is 2×27.7778=55.5556molesMass of ethanol= Molar Mass of ethanol × Number of moles={(12×2)+(1×6)+16} × 55.5556
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180= 27.7778molesIn the balanced equation of fermentation, the ratio of glucose to ethanol is 2:1Therefore the number of moles of ethanol is 2×27.7778=55.5556molesMass of ethanol= Molar Mass of ethanol × Number of moles={(12×2)+(1×6)+16} × 55.5556= 46.5×55.5556
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180= 27.7778molesIn the balanced equation of fermentation, the ratio of glucose to ethanol is 2:1Therefore the number of moles of ethanol is 2×27.7778=55.5556molesMass of ethanol= Molar Mass of ethanol × Number of moles={(12×2)+(1×6)+16} × 55.5556= 46.5×55.5556= 2555.55
Answer:
Answer:A
Answer:AExplanation:
Answer:AExplanation:Molar Mass of glucose = (6×12)+(1×12)+(16×6)= 180g/mol
= 180g/molNumber of moles of Glucose = Mass/Molar Mass
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180= 27.7778moles
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180= 27.7778molesIn the balanced equation of fermentation, the ratio of glucose to ethanol is 2:1
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180= 27.7778molesIn the balanced equation of fermentation, the ratio of glucose to ethanol is 2:1Therefore the number of moles of ethanol is 2×27.7778
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180= 27.7778molesIn the balanced equation of fermentation, the ratio of glucose to ethanol is 2:1Therefore the number of moles of ethanol is 2×27.7778=55.5556moles
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180= 27.7778molesIn the balanced equation of fermentation, the ratio of glucose to ethanol is 2:1Therefore the number of moles of ethanol is 2×27.7778=55.5556molesMass of ethanol= Molar Mass of ethanol × Number of moles
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180= 27.7778molesIn the balanced equation of fermentation, the ratio of glucose to ethanol is 2:1Therefore the number of moles of ethanol is 2×27.7778=55.5556molesMass of ethanol= Molar Mass of ethanol × Number of moles={(12×2)+(1×6)+16} × 55.5556
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180= 27.7778molesIn the balanced equation of fermentation, the ratio of glucose to ethanol is 2:1Therefore the number of moles of ethanol is 2×27.7778=55.5556molesMass of ethanol= Molar Mass of ethanol × Number of moles={(12×2)+(1×6)+16} × 55.5556= 46.5×55.5556
= 180g/molNumber of moles of Glucose = Mass/Molar Mass= 5000/180= 27.7778molesIn the balanced equation of fermentation, the ratio of glucose to ethanol is 2:1Therefore the number of moles of ethanol is 2×27.7778=55.5556molesMass of ethanol= Molar Mass of ethanol × Number of moles={(12×2)+(1×6)+16} × 55.5556= 46.5×55.5556= 2555.55
what is the molarity of a solutoin which contains 38.5 g of sodium chloride disolved in 325 ml solution ?
Answer:
Molarity = 2.02 M
Explanation:
Given data:
Molarity of solution = ?
Mass of sodium chloride = 38.5 g
Volume of solution = 325 mL (0.325 L)
Solution:
Number of moles = mass/molar mass
Number of moles = 38.5 g/ 58.44 g/mol
Number of moles = 0.658 mol
Molarity:
Molarity = number of moles / volume of solution in L
Molarity = 0.658 mol /0.325 L
Molarity = 2.02 M
A 2.54 g piece of zinc (density = 7.14 g/mL) is added to a graduated cylinder that contains 12.13 mL h2o. What will be the final volume reading on the graduated cylinder, in mL?
Answer: If I'm correct it's 12.54 mL but don't rely on this because I'm not sure
Explanation:
Answer:
12.49 ml
Explanation:
Density = mass / volume
Volume = mass / density
Volume of zinc = 2.54/7.14
Volume of zinc = 0.3557
Initial volume = 12.13 ml
Total volume = initial volume+ volume of zinc
Total volume = 12.13 + 0.3557
Total volume = 12.4857 = 12.49 ml
Conclusion
In this activity, thermal energy was transferred ( into / out of the hand warmer while it changed from
liquid to solid.
whats the question?
Insulin is a protein that is used by the body to regulate both carbohydrate and fat metabolism. A bottle contains 225 mL of insulin at a concentration of 20.0 mg/mL . What is the total mass of insulin in the bottle?
The total mass of insulin in the bottle : m = 4500 mg
Further explanationGiven
225 ml of insulin
The concentration 20 mg/ml
Required
The total mass of insulin
Solution
Density is the ratio of mass per unit volume
Can be formulated
ρ = m / V
m = ρ x V
Input the value :
m = 20 mg/ml x 225 ml
m = 4500 mg
Which two elements have similar characteristics?
Answer:
The two elements are FLUORINE AND CHLORINE. These two elements have similar characteristics because they belong to the same group in the periodic table. On the periodic table, elements with similar properties are grouped together in the same group. Both chlorine and fluorine belongs to the halogen group.
Explanation:
Hope it helps, some how.
Suppose 7.17g of barium acetate is dissolved in 350mL of a 79.0mM aqueous solution of sodium chromate. Calculate the final molarity of barium cation in the solution. You can assume the volume of the solution doesn't change when the barium acetate is dissolved in it. Round your answer to 1 significant digit.
Answer:
0.0802 M.
Explanation:
Hello!
In this case, since the barium acetate has the following formula:
[tex]Ba(CH_3COO)_2[/tex]
So its molar mass is 255.43 g/mol, in order to compute the molarity of the barium cation, we first need the moles in 7.17 g:
[tex]n_{Ba(CH_3COO)_2} = 7.17g*\frac{1molBa(CH_3COO)_2}{255.43g} =0.0281molBa(CH_3COO)_2[/tex]
Now, since one mole of barium acetate contains one mole of barium cations, we infer there are 0.0281 moles of barium cations. Moreover, since the molarity is computed by dividing the moles of those ones by the volume of the solution in liters, 350 mL (0.350 L) as it does not change, it turns out:
[tex]M=\frac{0.0281molBa^{2+}}{0.350L}\\\\M=0.0802M[/tex]
Best regards!
PLSSS HELP!! In the demonstration, Iron reacted with the oxygen in the air. Which one ran out
first? How do you know?
WHICH ONE IS TRUE WHICH ONE IS FALSE?
The number of valence electrons decreases from left to right across each period.
The number of valence electrons increases from top to bottom within each group.
All of the elements in group 9 have nine valence electrons.
Elements with the most valence electrons are in group 18.
Answer:
The number of valence electrons increases from top to bottom within each group.
Explanation:
The valence electrons are the outermost shell electrons.
Therefore, the number of valence electrons does not increase from top to bottom within each of the group.
Down a group, the number of valence electrons remains the same.
For group I elements, the number of electrons is 1.
The group is the vertical arrangement of elements.
From left to right across a period, the number of valence electrons increases because you move from group to group.
12. Which gas has the greatest kinetic energy at STP?
a. He
b. Ne
c. Ar
d. none of the above (all have the same kinetic energy)
Answer:
d. none of the above (all have the same kinetic energy)
Explanation:
The kinetic theory of gases states that the molecules of an ideal gas experience a constant random motion.
At standard temperature and pressure (STP), the kinetic energy of an ideal gas such as hydrogen, argon, neon, sodium, oxygen, helium, magnesium, beryllium, nitrogen, carbon, fluorine, chlorine etc are all the same.
The standard temperature and pressure (STP) of an ideal gas is 273K and 100 kPa.
Hence, all of the gases have the same kinetic energy at standard temperature and pressure (STP).
Kinetic energy can be defined as an energy possessed by an object or body due to its motion.
Mathematically, kinetic energy is given by the formula;
[tex] K.E = \frac{1}{2}MV^{2}[/tex]
Where, K.E represents kinetic energy measured in Joules.
M represents mass measured in kilograms.
V represents velocity measured in metres per seconds square.
HELP PLEASE
Instantaneous speed is the rate of motion at an instant in time. Based on this statement, a reasonable conclusion is that if and object's instantaneous speed does not chang over time then,________.
•the object is quickly speeding up
•the object is very gradually slowing down
•the object is moving at a constant speed
•the object has returned to its beginning position
Answer:
The object is moving at a constant speed.
the number that go before symbols and formulas in a chemicql equation are
A.SuperScripts
B.Subscripts
C.Catalysts
D.Coefficients
11. A 4.175 gram sample of a certain hydrate of copper (II) sulfate, CuSO,• xH,O, is heated until all
the water is driven off. The resulting anhydrous compound weighs 3.120 grams. What is the
formula of the hydrate?
The formula of the hydrate = CuSO₄• 3H₂O
Further explanationGiven
4.175 grams sample CuSO₄• xH₂O
3.120 grams anhydrous compound CuSO₄
Required
The formula
Solution
mass of H₂O driven off :
= 4.175 - 3.12
= 1.055 g
MW CuSO₄ = 159.5 g/mol
MW H₂O = 18 g/mol
mol ratio of CuSO₄ : H₂O :
= 3.12/159.5 : 1.055/18
= 0.01956 : 0.05861
= 1 : 3
Based on the data provided, the formula of the hydrated salt is CuSO4.3H20
What is the formula of the hydrate?The formula of the hydrate is determined from the mole ratio of the anhydrous saltand water.
Mass of water = 4.175 - 3.120
mass of water = 1.055 g
Mole ratio= mass/molar mass
molar mass of CuSO4 = 160 g/mol
molar mass of H2O = 18 g/mol
CuSO4 = 3.120/160 = 0.0195
H2O = 1.055/18 = 0.0586
CuSO4 = 0.0195/0.0195 = 1
H2O = 0.0586/0.0195 = 3
Therefore, the formula of the hydrated salt is CuSO4.3H20
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For the reaction of hydrogen with iodine
H2(g) + I2(g) rightarrow 2HI(g)
relate the rate of disappearance of hydrogen gas to the rate of formation of hydrogen iodide.
Answer:
[tex]r_{H_2} = \frac{-1}{2} r_{HI}[/tex]
Explanation:
Hello!
In this case, considering the given chemical reaction:
[tex]H_2(g) + I_2(g) \rightarrow 2HI(g)[/tex]
Thus, by applying the law of rate proportions, we can write:
[tex]\frac{1}{-1} r_{H_2} = \frac{1}{-1}r_{i_2} = \frac{1}{2} r_{HI}[/tex]
Whereas the stoichiometric coefficients of reactants are negative due their disappearance and that of the product is positive due to its appearance. In such a way, when we relate the rate of disappearance of hydrogen gas to the rate of formation of hydrogen iodide, we obtain:
[tex]r_{H_2} = \frac{-1}{2} r_{HI}[/tex]
Best regards!
Chromuate found inside which of the following structures of a eukaryotic cell?
Answer:
Chromuates are found in the chromosomes of the eukaryotic cells!!!!
Explanation:
I learned this in 7th grade!!!!
Mark Me Brainliest plzz
all organisms begins life as a ________ cell.
Answer:
All organisms begin life as a single cell
Explanation:
Single cell also did you know 15 minutes can save you 15% more on car insurance
Which of the following represents a compound made of five molecules
OCOS
OC205
Осо
5002
is water vapor only found in hot water?
What is the mass of 1.0 × 10^9 molecules of aspartame?
Answer:
294.3 g/mol b.
The mass of 1.0*10^9 molecules of aspartame is 2.943*10^11 g/mol
ASPARTAME
Aspartame is used as an artificial non-saccharide sweetener 200 times sweeter than sucrose, and is commonly used as a sugar substitute in foods and beverages.
CALCULATION
mass of one molecule of aspartame = 294.3g/mol
mass of 1.0*10^9 molecules of aspartame =294.3*(1.0*10^9) g/mol
=2.943*10^11 g/mol
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