According to the reaction H2 + Cl2 = 2HCl the production of 2.0 moles of
HCI would require 70. grams of Cl2. How many grams of H, would be
needed? *

2.02 grams of hydrogen gas reacted to form 2 moles of HCl.

Explanation:

Data given:

moles of HCl = 2

chlorine required = 70 grams

atomic mass of chlorine gas = 70.906 grams/mole

grams of H required=?

balanced chemical reaction:

+  ⇒ 2HCl

number of moles of chlorine gas  =

number of moles of chloride gas  = 0.98 or 1 mole

So 1 mole hydrogen and 1 mole chlorine gas reacted to form 2 mole of HCl

molar mass of 1 mole of hydrogen gas = 2.02 grams/mole

mass = number of moles x molar mass

mass = 1 x 2.02

mass = 2.02 grams

so, 70 gram or 1 mole chlorine gas and 1 mole or 2.02 grams of hydrogen gas reacted to form 2 moles of HCl.