The rate constant of a first order reaction is 15×10-3 s-1⋅ How long will 5.0 g of this reactant take to reduce to 3.0 g?

Question

The rate constant of a first order reaction is 15×10-3 s-1⋅ How long will 5.0 g of this reactant take to reduce to 3.0 g? (A) 34.07 s (B) 7.57 s (C) 10.10 s (D) 15 s

Tardigrade Admin · Accepted Answer

t=(2.303/k) log (a/(a-x)) or t=(2.303/15×10-3) log (5/3)=34.07 s

Q. The rate constant of a first order reaction is $15 \times 1 0^{- 3} s^{- 1} \cdot$ How long will $5.0 g$ of this reactant take to reduce to $3.0 g$ ?

$34.07 s$

$7.57 s$

$10.10 s$

$15 s$

$t = \frac{2.303}{k} l o g \frac{a}{( a - x )}$
or $t = \frac{2.303}{15 \times 1 0 ^{- 3}} l o g$ $\frac{5}{3} = 34.07 s$

Q. The rate constant of a first order reaction is 15×10−3s−1⋅ How long will 5.0g of this reactant take to reduce to 3.0g?

34.07s

7.57s

10.10s

15s