1. Which of the following does the concept of material balance based upon?
a) Conservation of mass
b) Conservation of energy
c) Conservation of momentum
d) Conservation of Volume
Explanation: Material is simply conservation of mass.
2. The equation of material balance, (Final condition + Sum of outputs) is equal to which of the following?
a) Initial condition – Sum of inputs
b) Initial condition + Sum of inputs
c) Sum of inputs – Initial condition
d) None of the mentioned
Explanation: Equation of material balance is Final condition – Initial condition = Sum of inputs – Sum of outputs, => Final condition + Sum of outputs = Initial condition + Sum of inputs
3. A container has 10 grams of water 5 grams of water is added and 2 grams of water is taken out, what is the final amount of water?
a) 7 grams
b) 10 grams
c) 13 grams
d) 15 grams
Explanation: Final condition = Initial condition + sum of inputs – sum of outputs = 10 + 5 – 2 = 13 grams.
4. 10 moles of O2 is added to 10 moles of H2, how many moles of H2O will it produce?
a) 5
b) 10
c) 15
d) 20
Explanation: Balanced equation is 2H2 + O2 -> 2H2O, => Moles of H2O = Moles of H2 = 10.
5. A combustion reaction has reactants 1 mole of CxHy and 2 moles of O2 and products 1 mole of CO2 and 2 mole of H2O, what is x + y?
a) 1
b) 3
c) 4
d) 5
Explanation: Moles of C, H and O in reactants = Moles of C, H and O in products, => C: 1*x = 1*1 => x = 1, H: 1*y = 2*2 => x + y = 5.
6. In a random reaction 2 mole of CH4 and 1 mole of C2H4 are reacted, and 1 mole of C3H8 and 1 mole of CxHy are produced, what is x*y?
a) 2
b) 4
c) 8
d) 12
Explanation: Material balance for C: 2*1 + 1*2 =1*3 +1*x, => x = 1, for H: 2*4 + 1*4 = 1*8 + 1*y, => y = 4, => x*y = 4.
7. A reaction has reactants 2 moles of NaOH and 1 mole of H2SO4, and products Na2SO4 and H2O, what are the total moles of products?
a) 1
b) 2
c) 3
d) 4
Explanation: Material Balance for Na: 2*1 = n1*2 => n1 = 1, for H: 2*1 + 1*2 = n2*2 => n2 = 2, => total moles of products = 1 + 2 = 3.
8. A reaction is A + 2B -> 3C, if 2 moles of A and 4 moles of B entered the system, what are the number of moles of C formed?
a) 2
b) 4
c) 6
d) 8
Explanation: Moles of C = 3*2 = 6.
9. 10 moles of A were present in a system initially, and 10 moles are added to it, it follows the reaction 4A -> B, what are the number of moles of B produced?
a) 5
b) 10
c) 15
d) 20
Explanation: Moles of B = (10 + 10)/4 = 5.
10. 10 moles of A were present in a system initially, and 10 moles of C are added to it, it follows the reaction 2A + C -> 5B, what is the number of moles of B produced?
a) 5
b) 10
c) 25
d) 50
Explanation: Mole of B = 5*5 = 25.