Suppose we have an object with a surface area of $S=1.5~\mathrm{dm^2}$, and we need to coat it with hard chrome. The thickness of the coat should be $d=80~\mathrm{\mu m}$. The mixture used for coating is of the following mixture: $\ce{CrO3}$ $290~\mathrm{g/L}$, $\ce{H2SO4}$ $2.5~\mathrm{g/L}$. The current density is $J = 50~\mathrm{A~dm^{-2}}$. The current utilization factor is $\mu = 15\%$. Using Faraday's law of electrolysis: $$\frac{m}{M}=\frac{q}{F}$$ and the fact that $$J_{\mathrm{actual}}=0.15\cdot\frac{q}{S\Delta t}$$ where $S$ represents the surface through which the constant current passes through, I got $\Delta t = 1425~\mathrm{s}$, however the answer is $\Delta t = 2~\mathrm{h}~22~\mathrm{min}$.

Suppose we have an object with a surface area of $S=\pu{1.5 dm2}$, and we need to coat it with hard chrome. The thickness of the coat should be $d=\pu{80 \mu m}$. The mixture used for coating is of the following mixture: $\ce{CrO3}$ $\pu{290 g/L}$, $\ce{H2SO4}$ $\pu{2.5 g/L}$. The current density is $J = \pu{50 A dm-2}$. The current utilization factor is $\mu = 15\%$. Using Faraday's law of electrolysis: $$\frac{m}{M}=\frac{q}{F}$$ and the fact that $$J_{\mathrm{actual}}=0.15\cdot\frac{q}{S\Delta t}$$ where $S$ represents the surface through which the constant current passes through, I got $\Delta t = \pu{1425 s}$, however the answer is $\Delta t = \pu{2 h 22 min}$.

Suppose we have an object with a surface area of $S=1.5 dm^{2}$, and we need to coat it with hard chrome. The thickness of the coat should be $d=80\mu m$. The mixture used for coating is of the following mixture: $CrO_{3}$ $290 $ g/L, $H_{2}SO_{4}$ $2.5$ g/L. The current density is $J=50 \frac{A}{dm^2}$. The current utilization factor is $\mu=15$%. Using Faraday's law of electrolysis: $$\frac{m}{M}=\frac{q}{F}$$ and the fact that $$J_{actual}=0.15 \frac{q}{S*\Delta t}$$ where S represents the surface through which the constant current passes through, I got $\Delta t=1425 s$, however the answer is $\Delta t= 2h 22 min$.

Suppose we have an object with a surface area of $S=1.5~\mathrm{dm^2}$, and we need to coat it with hard chrome. The thickness of the coat should be $d=80~\mathrm{\mu m}$. The mixture used for coating is of the following mixture: $\ce{CrO3}$ $290~\mathrm{g/L}$, $\ce{H2SO4}$ $2.5~\mathrm{g/L}$. The current density is $J = 50~\mathrm{A~dm^{-2}}$. The current utilization factor is $\mu = 15\%$. Using Faraday's law of electrolysis: $$\frac{m}{M}=\frac{q}{F}$$ and the fact that $$J_{\mathrm{actual}}=0.15\cdot\frac{q}{S\Delta t}$$ where $S$ represents the surface through which the constant current passes through, I got $\Delta t = 1425~\mathrm{s}$, however the answer is $\Delta t = 2~\mathrm{h}~22~\mathrm{min}$.