A solution is a homogeneous mixture.

What are the molality and mole fraction of solute in a 35.9 percent by mass aqueous solution of formic acid (HCOOH)?

sdas [7]

ِAnswer:

1- The molarity of HCOOH = 9.515 M.

2- The mole fraction of HCOOH = 0.18.

Explanation:

1- The molarity of HCOOH:

We can calculate the molarity of HCOOH using the relation:

M = (10pd)/molar mass.

p is the percent by mass of HCOOH = 35.9 %.

d is the specific gravity of HCOOH = 1.22 g/cm³.

Molar mass of HCOOH = 46.03 g/mol.

∴ M = (10pd)/molar mass = (10)(35.9 %)(1.22 gcm³) / (46.03 g/mol) = 9.515 M.

2- The mole fraction of HCOOH:

We can suppose that we have a 100 g solution, that contains 35.9 g of HCOOH and 64.1 g of water.

The mole fraction of HCOOH = (no. of moles of HCOOH) / (no. of moles of HCOOH + no, of moles of water).

no. of moles of HCOOH = mass / molar mass = (35.9 g)/(46.03 g/mol) = 0.78 mol.

no. of moles of water = mass / molar mass = (64.1 g)/(18.0 g/mol) = 3.56 mol.

The mole fraction of HCOOH = (no. of moles of HCOOH) / (no. of moles of HCOOH + no, of moles of water) = (0.78 mol) / (0.78 mol + 3.56 mol) = 0.18.

7 0

3 years ago

Boyle's law states that gas volume is Boyle's law states that gas volume is inversely proportional to temperature. directly prop

ankoles [38]

Answer: Boyle's law states that gas volume is inversely proportional to pressure.

Explanation:

Boyle's law is one of the law used to determine the Ideal Gas equation.

This law states that pressure of the gas is inversely proportional to the volume of the gas at constant temperature and number of moles

Mathematically,

$P\propto \frac{1}{V}$ (at constant temperature and number of moles)

The above expression can also be written as:

$P_1V_1=P_2V_2$

where,

$P_1\text{ and }V_1$ are initial pressure and volume of the gas

$P_2\text{ and }V_2$ are final pressure and volume of the gas

Hence, Boyle's law states that gas volume is inversely proportional to pressure.

8 0

2 years ago

Read 2 more answers

How many moles of electrons is required to deposit 5.6g of iron from a solution of iron (2) tetraoxosulphate(6)

yuradex [85]

Answer:

0.20 mol

Explanation:

Let's consider the reduction of iron from an aqueous solution of iron (II).

Fe²⁺ + 2 e⁻ ⇒ Fe

The molar mass of Fe is 55.85 g/mol. The moles corresponding to 5.6 g of Fe are:

5.6 g × 1 mol/55.85 g = 0.10 mol

2 moles of electrons are required to deposit 1 mole of Fe. The moles of electrons required to deposit 0.10 moles of Fe are

0.10 mol Fe × 2 mol e⁻/1 mol Fe = 0.20 mol e⁻

7 0

3 years ago

Look at the following reaction. How could you increase the production of 2NH3(g)? N2(g) + 3H2(g) 2NH3(g) Increase the volume of

Zolol [24]

The correct option is B. To increase the production of ammonia, you have to increase the pressure of the system. Increase in pressure will result in increased production of ammonia because this will drive the chemical reaction forward.

5 0

3 years ago

Read 2 more answers

When 3.93 grams of lactic acid, CHoOs(s), are burned in a bomb

aliya0001 [1]

The heat released in the combustion of lactic acid is absorbed by the

calorimeter and in the decomposition of the lactic acid.

ΔH°f of lactic acid is approximately -716.2 kJ

Reasons:

Known parameters are;

Mass of the lactic acid = 3.93 grams

Heat capacity of the bomb calorimeter = 10.80 kJ·K⁻¹

Change in temperature of the calorimeter, ΔT = 5.34 K

ΔHrxn = ΔErxn

ΔH°f of H₂O(l) = -285.8 kJ·mol⁻¹

ΔH°f of CO₂(g) = -393.5 kJ·mol⁻¹

The chemical equation for the reaction is presented as follows;

C₃H₆O₃ + 2O₂ → 3CO₂ + 3H₂O

The heat of the reaction = 10.80 kJ·K⁻¹ × 5.34 K = 57.672 kJ

Molar mass of C₃H₆O₃ = 90.07 g/mol

Number of moles of C₃H₆O₃ = $\dfrac{3.93 \, g}{90.07 \, g/mol}$ = 0.043633 moles

Number of moles of CO₂ produced = 3 × 0.043633 moles = 0.130899 moles

Heat produced = 0.130899 mole × -285.8 kJ·mol⁻¹ = -37.4109342 kJ

Moles of H₂O produced = 0.130899 moles

Heat produced = 0.130899 mole × -393.5 ≈ -51.51 kJ

Therefore, we have;

Heat absorbed by the lactic acid = ΔH°f of H₂O + ΔH°f of CO₂ + Heat absorbed by the calorimeter

Which gives;

Heat absorbed by lactic acid = -37.4109342 kJ - 51.51 kJ + 57.672 kJ ≈ -31.249 kJ

The heat absorbed by the lactic acid ≈ -31.249 kJ

$\Delta H^{\circ}f \ of \ C_3H_6O_3 = \dfrac{-31.249}{0.043633} \approx -716.2$

ΔH°f of C₃H₆O₃ ≈ -716.2 kJ

Heat of formation of lactic acid ≈ -716.2 kJ.

Learn more here:

brainly.com/question/13185938

5 0

2 years ago