15.23 c

[Gabriela Carrillo 1B]

If given the molarity of how much product was formed, how would you use dimensional analysis to figure out [A]?

[Ashin_Jose_1H]

We know that two moles of A are consumed to produce 1 mole of B. Therefore, we can calculate the resulting concentration by multiplying the concentration of B by two. Since we are given the initial concentration of A, the concentration of A at time t, would be the initial concentration minus the resulting concentration we calculated.

[Yutian Zhao -1J]

according to unique reaction rate law: -(1/a)*delta[A]/delta t= (1/b)*delta[B]/delta t, we can cancel delta t on both sides since they are the same, then we know that a=2, b=1, and we also know delta[B] =0.034mol/L since [B]initial is zero. Then we can derive delta[A] from the equation. since we also know the initial [A] is 0.153mol/L, we can use initial[A]- delta[A] to get [A] at 115s. Hope it helps.