The half-life of a first-order reaction is independent of the initial concentration. What is the expression for the half-life (t1/2) of a first-order reaction? (2022)
Practice Questions
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Q1
The half-life of a first-order reaction is independent of the initial concentration. What is the expression for the half-life (t1/2) of a first-order reaction? (2022)
t1/2 = 0.693/k
t1/2 = k/0.693
t1/2 = 1/k
t1/2 = k/2
The half-life of a first-order reaction is given by the formula t1/2 = 0.693/k, where k is the rate constant.
Questions & Step-by-step Solutions
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Q
Q: The half-life of a first-order reaction is independent of the initial concentration. What is the expression for the half-life (t1/2) of a first-order reaction? (2022)
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.
Steps: 5
Step 1: Understand what half-life means. Half-life is the time it takes for half of a substance to react or decay.
Step 2: Recognize that we are talking about a first-order reaction. In this type of reaction, the rate depends only on the concentration of one reactant.
Step 3: Note that for first-order reactions, the half-life does not change with different starting amounts of the reactant.
Step 4: Learn the formula for the half-life of a first-order reaction, which is t1/2 = 0.693/k.
Step 5: Identify that 'k' in the formula is the rate constant, which is a specific value for each reaction.
