# Chemical Engineering Questions and Answers – Concentration

This set of Basic Chemical Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Concentration”.

1. Which of the following is not the unit of concentration?
a) Mole/m3
b) Molar
c) N/m3
d) ppm

Explanation: Concentration is moles per unit volume or mass per unit volume, so N/m3 cannot be a unit of concentration.

2. What is the concentration of a 22 grams of carbon dioxide occupying 0.5 m3 volume?
a) 1 mole/m3
b) 2 mole/m3
c) 11 mole/m3
d) 22 mole/m3

Explanation: Moles of carbon dioxide = 22/44 = 0.5, => concentration = 0.5/0.5 = 1 mole/m3.

3. What is the concentration of 100 lbs. of solution occupying 25 m3 of volume?
a) 1.8 Kg/m3
b) 2.7 Kg/m3
c) 4 Kg/m3
d) 8 Kg/m3

Explanation: Mass of solution = 100*0.453 = 45.3 kg, => Concentration of solution = 45.3/25 = 1.8 kg/m3.

4. What is the molarity of a solution with a mass of solute 10 kg mass and 100 liter volume?
a) 0.1 molar
b) 1 molar
c) 10 molar
d) 100 molar

Explanation: Molarity = 10/100 = 0.1 molar.

5. What is the concentration of a solution with 10 grams of calcium in 1000 m3 of water?
a) 150 ppm
b) 250 ppm
c) 800 ppm
d) 1000 ppm

Explanation: Moles of calcium = 10/40 =0.25, => concentration in ppm = (0.25/1000)*106 = 250 ppm.
Note: Join free Sanfoundry classes at Telegram or Youtube

6. How much Sodium is there in a solution with 10 Kg of solvent (Density = 5 Kg/m3) and concentration 4 molar?
a) 23 grams
b) 92 grams
c) 184 grams
d) 276 grams

Explanation: Volume of solvent = 10/5 = 2 m3, => moles of sodium = 4*2 = 8 moles, => mass of sodium = 8*23 = 184 grams.

7. A 5 molar solution is 27.75% CaCl2 by mass, what is the density of the solution?
a) 1 g/cm3
b) 2 g/cm3
c) 3 g/cm3
d) 4 g/cm3

Explanation: Let the mass of Solution be 100 grams, => moles of CaCl2 = 27.75/111 = 0.25, Density of solution = 5*(100/0.25) = 2000 kg/m3 = 2 g/cm3.

8. A solution with density 1 g/cm3 has 98 grams of H2SO4 in 402 grams of water, what is the concentration of solution?
a) 1 molar
b) 2 molar
c) 3 molar
d) 4 molar

Explanation: Moles of H2SO4 = 98/98 = 1, => concentration of solution = 1/(500/1) = 2*10-6 mole/cm3 = 2 molar.

9. A solution with density 2 g/cm3, concentration 1 molar and weight 500 grams, then what is the mass of HNO3 in the solution?
a) 63 grams
b) 126 grams
c) 189 grams
d) 252 grams

Explanation: Moles of HNO3 = 1/(500/2000) = 4, = > mass of HNO3 = 4*63 = 252 grams.

10. What is the molarity of the mixture of two solution, first solution 4 M and 10 liter and second solution 2 M and 40 liter?
a) 1.2 M
b) 2.4 M
c) 4.8 M
d) 9.2 M

Explanation: Molarity of mixture = (M1V1 + M2V2)/(V1 + V2) = (4*10 + 2*40)/ (10 + 40) = 2.4 M.

11. What is the molar concentration of a solution with 40 gram of NaOH in 1 liter solution?
a) 1 mole/liter
b) 2 mole/liter
c) 3 mole/liter
d) 4 mole/liter

Explanation: Molar concentration = (40/40)/1 = 1 mole/liter.

12. What is the molar concentration of a solution with 32 grams of CH4 in 1 liter solution?
a) 1 mole/liter
b) 2 mole/liter
c) 3 mole/liter
d) 4 mole/liter

Explanation: Molar concentration = (32/16)/1 = 2 mole/liter.

13. What is the molar concentration of a solution with 44 grams of CO2 in 0.5 liter solution?
a) 1 mole/liter
b) 2 mole/liter
c) 3 mole/liter
d) 4 mole/liter

Explanation: Molar concentration = (44/44)/0.5 = 2 mole/liter.

14. What is the molar concentration of a solution with 32 grams of SO2 in 0.5 liter solution?
a) 1 mole/liter
b) 2 mole/liter
c) 3 mole/liter
d) 4 mole/liter

Explanation: Molar concentration = (32/64)/0.5 = 1 mole/liter.

15. What is the molar concentration of a solution with 49 grams of H2SO4 in 0.5 liter solution?
a) 1 mole/liter
b) 2 mole/liter
c) 3 mole/liter
d) 4 mole/liter

Explanation: Molar concentration = (49/98)/0.5 = 1 mole/liter.

Sanfoundry Global Education & Learning Series – Basic Chemical Engineering.

To practice all areas of Basic Chemical Engineering, here is complete set of 1000+ Multiple Choice Questions and Answers.