Homework Help: Concentration and Reaction

Posted by Confused on Saturday, November 20, 2010 at 10:36pm.

The rate of the following reaction:
Radioactive decay of 90Sr,
is characterized by the rate constant k = 0.024 year-1. What is the half-life (in years) for this reaction at the same conditions when the initial concentrations are 0.0356 M? (Round your answer to 3 significant figures.)
Hint: The units of the rate constant are linked with the order of reaction.

Answer:________________years

Concentration and Reaction - DrBob222, Saturday, November 20, 2010 at 11:10pm
Radioactive decay is a first order reaction. t_1/2 = 0.693/k
Solve for t_1/2.
It doesn't matter that conditions are changed, the half-life is the same; half life of first order reactions don't depend upon the initial concn. You can show that, however, by using
ln(No/N) = kt
Substitute 0.0356 M for No and half that for N and 0.024 for k. t_1/2 will be the same as obtained by 0.693/0.024.

Answer this Question

Related Questions

college chemistry - The rate of the following reaction: 2 NO2 2 NO + O2, is ...
Chemistry Lab - What would happen to the reaction rate of a solution if 10 mL or...
Chemistry Lab - What would happen to the reaction rate of a solution if 10 mL or...
chemistry - What is the rate of the following reaction (M/s) if the rate ...
Chemistry - In a reversible reaction, chemical equilibrium is attained when ? 1...
chemistry - The rate law of the overall reaction. A + B -> C is rate = k...
chemistry - The following reaction is a single-step, bimolecular reaction: CH3Br...
chemistry - The reaction A + B + C = products has a rate law rate = kA]C]2. ...
Chemistry - A reaction is said to be diffusion controlled when it occurs as fast...
Organic Chem - The following reaction is a single-step, bimolecular reaction: ...

For Further Reading

First Name:
School Subject:
Answer: