If a reaction mixture is initially 0.35 m in x, what is the concentration of x after 190 seconds? if a reaction mixture is initially 0.35 in , what is the concentration of after 190 seconds? 0.00 m 0.11 m 0.34 m 0.21 m

According to the second-order rate constant formula:

K t = 1/[At]  - 1/[Ao]

when k is the rate constant = 0.035 (given missing in your question)

and t is the time = 190 sec

Ao is the initial concentration of X = 0.35 m 

by substitution:

0.035 * 190 sec = 1/[At]  - 1/0.35

∴ [At] = 0.11 m

∴ the concentration after 190 sec = 0.11 m