In the synthesis of $\text{NH}_3$ from $\text{H}_2$ and $\text{N}_2$ if $6\times10^{-2}$ mole of hydrogen disappears in 10 minutes, the number of moles of $\text{NH}_3$ formed in 3 minutes is:
Show Hint
To simplify tracking multi-step kinetics, convert everything to a $1$-minute baseline first! $6\times10^{-2}$ over $10$ minutes is $6\times10^{-3}$ per minute. Multiplying by $0.3$ minutes gives $1.8\times10^{-3}$ moles of $\text{H}_2$. Applying the $\frac{2}{3}$ multiplier directly yields $1.2\times10^{-3}$ moles of $\text{NH}_3$ instantly.