Question

Chloroform, CHCl₃, is prepared industrially by the reaction of methane (CH₄) with chlorine. How many grams of Cl2 are needed to produce 1.50 moles of chloroform?

Answer 1

The balanced equation for the reaction between methane and chlorine is:

CH₄ + Cl₂ $\rightarrow$ CH₃Cl + HCl.

As it can be seen from this equation, when 1 mole of chlorine reacts, 1 mole of chloroform is formed:

$n(Cl_2) = n(CH_3Cl)$ .

Therefore, to produce 1.50 moles of chloroform, the number of the moles of chloroform needed is also 1.50 moles.

The mass $m$ of a compound can be calculated as a product of its number of the moles $n$ and its molar mass $M$ :

$m = n\cdot M$ .

The molar mass of chlorine is 70.91 g/mol. Thus, the mass of chlorine needed is:

$m(Cl_2) = 1.50\text{ mol}\cdot70.91\text{ g/mol} = 106.4$ g.

Answer: 106.4 grams of Cl₂ are needed to produce 1.50 moles of chloroform from methane.