How many grams of methane chloride can be obtained from 80 grams of methane?

Given:
m (CH4) = 80 g

Find:
m (CH3Cl) -?

Solution:
1) Write the reaction equation:
CH4 + Cl2 => CH3Cl + HCl;
2) Calculate the molar masses of CH4 and CH3Cl:
M (CH4) = 16 g / mol;
M (CH3Cl) = 50.5 g / mol;
3) Calculate the amount of substance CH4:
n (CH4) = m (CH4) / M (CH4) = 80/16 = 5 mol;
4) Determine the amount of CH3Cl substance (taking into account the coefficients in the reaction equation):
n (CH3Cl) = n (CH4) = 5 mol;
5) Calculate the mass of CH3Cl:
m (CH3Cl) = n (CH3Cl) * M (CH3Cl) = 5 * 50.5 = 252.5 g.

Answer: The mass of CH3Cl is 252.5 g.