This set of Extractive Metallurgy Multiple Choice Questions & Answers (MCQs) focuses on “Chemical Equilibrium”.
1. In which of the following process the temperature of a reaction remains constant?
a) Isothermal
b) Isotropic
c) Isobaric
d) Isotopic
View Answer
Explanation: In the isothermal process, the temperature of a reaction remains constant. This means that the temperature at the beginning and end of the reaction remains the same. The temperature does not need to remain unchanged, changes may occur during the process.
2. What is the stablest state of a pure substance called?
a) Subscript state
b) Superscript state
c) Isobaric state
d) Standard state
View Answer
Explanation: At an isothermal temperature and one atmospheric pressure, a pure substance reaches its stablest state which is called standard state. It could be pure solid or liquid or gas.
3. Fugacity is equal to partial pressure for ideal gases.
a) True
b) False
View Answer
Explanation: Fugacity of a real gas is an effective partial pressure which is determined experimentally from models like ‘Van der Waals gases’. For an ideal gas, it is equal to partial pressure, which has the same temperature and energy as a real gas.
4. The equation used to measure the relative amounts of products and reactants for a particular reaction is called?
a) Equilibrium constant
b) Activity quotient
c) Catalyst
d) Activity
View Answer
Explanation: Activity quotient is an equation used to measure the relative amounts of reactants and products for a particular reaction at a particular time. Activity quotient is derived at an isothermal condition. It helps in determining the direction of the reaction which can take place.
5. In the equation given below, what does ‘K’ refer to?
ΔG = -RTln(K)
a) Equilibrium constant
b) Temperature
c) Activity
d) Gas constant
View Answer
Explanation: The above-given equation is for the change in free energy. The ‘K’ is referred to as an equilibrium constant. It is the value of activity quotient at equilibrium. It determines the direction of a reaction which is taking place.
6. Which of the following is the required condition for thermodynamic predictions and calculations?
a) The temperature should be increasing
b) The temperature should be decreasing
c) Standard free energy change should be available
d) Standard free energy change should be absent
View Answer
Explanation: There are some required conditions for the thermodynamic predictions and calculations. One of which is that the standard free energy change should be available. Other conditions are that the process should be isothermal and the temperature should be available. Also, activity versus composition relations should be known.
7. What can be concluded if ΔG in the following equation is negative?
ΔG = ΔG° + RT lnQ
a) The reaction is not feasible
b) The reaction is not spontaneous
c) Reaction is impossible
d) Reaction is spontaneous
View Answer
Explanation: The above-given equation is used as a basis to predict the feasibility of a reaction. If ΔG is negative in the above reaction then, the reaction is feasible and spontaneous. If ΔG is positive then the reaction is not possible.
Sanfoundry Global Education & Learning Series – Extractive Metallurgy.
To practice all areas of Extractive Metallurgy, here is complete set of Multiple Choice Questions and Answers.
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