15) The following reaction is second onler in A and the rate constant is 0.025M^-1s^-1 Aarrow B The concentration of A was 0.65 M at 33 s. The initial concentration of A was __ M A) 2.4 B) 0.27 C) 0.24 D) 1,4 E) 1.2times 10^-2 Answer: D 18) The rate constant of a first-order process that has a half-life of 3.50 min is s^-1 A) 0.693 B) 1.65times 10^-2 C) 1.98 D) 0.198 E) 3.30times 10-3 Answe r: E

15) The following reaction is second order in $\{ A\} $ and the rate constant is $0.025M^{-1}s^{-1}$<br />$A\rightarrow B$<br />The concentration of A was 0.65 M at 33 s. The initial concentration of A was __ M<br />A) 2.4<br />B) 0.27<br />C) 0.24<br />D) 1.4<br />E) $1.2\times 10^{-2}$<br />Answer: D<br /><br />18) The rate constant of a first-order process that has a half-life of 3.50 min is $s^{-1}$<br />A) 0.693<br />B) $1.65\times 10^{-2}$<br />C) 1.98<br />D) 0.198<br />E) $3.30\times 10^{-3}$<br />Answer: E