Posted by **mandy** on Monday, May 3, 2010 at 9:44pm.

10% of a sample reacts in 25 s. If the reaction follows first order kinetics, how long would it take for half the sample to react?

- Chemistry -
**DrBob222**, Monday, May 3, 2010 at 10:20pm
ln(No/N) = kt

If we start with an arbitrary number, say 100, and 10% is used, that would leave 90

ln(100/90) = k(25sec)

solve for k. You want the half life; therefore, substitute the k you find in the same equation but this time start with 100 and N = 50 (half is gone). Solve for t and that will be t_{1/2}

- Chemistry -
**Anonymous**, Friday, March 22, 2013 at 12:17am
Ei

## Answer this Question

## Related Questions

- chemistry - Radioactive decay is a process that follows first-order kinetics. ...
- chemistry - If the breakdown half-life of a pesticide applied to a farmer’s ...
- Chemistry - Gallium65, a radioactive isotope of gallium, decays by first order-...
- Chemistry - The given reaction, 2N2O5 4NO2 + O2, follows first-order kinetics ...
- Chemistry - What is the value of the rate constant for a reaction in which 75.0 ...
- Chemistry - What is the value of the rate constant for a reaction in which 75.0 ...
- Inorganic chemistry - The decopostion of formic acid follows first-order ...
- chemistry - follows first-order kinetics and has an activation energy of 244 kJ ...
- chemistry - What is the half-life of a compound if 69 percent of a given sample ...
- chemistry - The given reaction, cyclopropane propene (isomerization), follows ...

More Related Questions