Q. The half-life of a first-order reaction is independent of the initial concentration of the reactant. What is the expression for the half-life (t1/2) of a first-order reaction? (2020)
A.
t1/2 = 0.693/k
B.
t1/2 = k/0.693
C.
t1/2 = 1/k
D.
t1/2 = k/1
Solution
The half-life of a first-order reaction is given by the formula t1/2 = 0.693/k, which shows that it is independent of the initial concentration.
Q. The half-life of a first-order reaction is independent of the initial concentration of the reactant. What is the formula for the half-life (t1/2) of a first-order reaction? (2020)
A.
t1/2 = 0.693/k
B.
t1/2 = k/0.693
C.
t1/2 = 1/k
D.
t1/2 = k/1
Solution
The half-life of a first-order reaction is given by the formula t1/2 = 0.693/k, where k is the rate constant.
Q. The half-life of a first-order reaction is independent of the initial concentration of the reactant. What is the expression for the half-life (t₁/₂)? (2022)
A.
t₁/₂ = 0.693/k
B.
t₁/₂ = k/0.693
C.
t₁/₂ = 1/k
D.
t₁/₂ = k/1
Solution
The half-life of a first-order reaction is given by t₁/₂ = 0.693/k.
Q. The half-life of a first-order reaction is independent of the initial concentration of the reactant. What is the expression for the half-life? (2022)
A.
t₁/₂ = 0.693/k
B.
t₁/₂ = k/0.693
C.
t₁/₂ = 1/k
D.
t₁/₂ = k/1
Solution
The half-life of a first-order reaction is given by t₁/₂ = 0.693/k.
Q. The Hardy-Weinberg principle describes the genetic equilibrium in a population. Which of the following is NOT a condition for this equilibrium? (1908)
A.
No mutations
B.
Random mating
C.
Natural selection
D.
Large population size
Solution
Natural selection is not a condition for Hardy-Weinberg equilibrium; it actually disrupts genetic equilibrium by favoring certain alleles over others.
Q. The heat capacity at constant volume is defined as: (2023)
A.
C_v = dQ/dT at constant pressure
B.
C_v = dQ/dT at constant volume
C.
C_v = dW/dT at constant volume
D.
C_v = dQ/dP at constant volume
Solution
The heat capacity at constant volume (C_v) is defined as the amount of heat added to the system divided by the change in temperature at constant volume.
Correct Answer:
B
— C_v = dQ/dT at constant volume
Q. The heat capacity of a substance is defined as: (2023)
A.
The amount of heat required to raise the temperature of one gram by one degree Celsius.
B.
The amount of heat required to raise the temperature of one mole by one degree Celsius.
C.
The total heat content of the substance.
D.
The heat required to change the state of the substance.
Solution
The heat capacity of a substance is defined as the amount of heat required to raise the temperature of one mole of the substance by one degree Celsius.
Correct Answer:
B
— The amount of heat required to raise the temperature of one mole by one degree Celsius.
Q. The impedance of an RLC circuit is minimum when which condition is satisfied? (2022)
A.
XL = XC
B.
R = 0
C.
R = XL
D.
R = XC
Solution
The impedance (Z) of an RLC circuit is minimum when the inductive reactance (X_L) equals the capacitive reactance (X_C), which is the condition for resonance.