# Carbon disulfide, CS2 can be made from coke, C and sulfur dioxide, SO2: 3C + 2 SO2→ CS2 + CO2. If the actual yield of CS2 is 86% of the theoretical yield, what mass of coke is needed to produce 950g of CS2?

Jul 31, 2017

$523$ $\text{g C}$

#### Explanation:

Since $950$ $\text{g}$ is the desired mass of ${\text{CS}}_{2}$, and the percent yield is 86%, the theoretical yield of ${\text{CS}}_{2}$ is

$950$ $\text{g CS"_2}$ xx 100/86 = ul(1107color(white)(l)"g CS"_2

Now, let's convert this value to moles, using the molar mass of carbon disulfide:

1107cancel("g CS"_2)((1color(white)(l)"mol CS"_2)/(76.14cancel("g CS"_2))) = color(red)(14.5 color(red)("mol CS"_2

Now, we use the coefficients of the chemical equation to find the relative number of moles of $\text{C}$:

color(red)(14.5)cancel(color(red)("mol CS"_2))((3color(white)(l)"mol C")/(1cancel("mol CS"_2))) = color(green)(43.5 color(green)("mol C"

Finally, we use the molar mass of coke (carbon) to find the mass:

color(green)(43.5)cancel(color(green)("mol C"))((12.011color(white)(l)"g C")/(1cancel("mol C"))) = color(blue)(ul(523color(white)(l)"g C"