Question

Hydrogen chloride is prepared using the reaction: _NaCl(aq) + _H2SO4(aq) → _HCl(g) + _Na2SO4(aq) What is the theoretical yield in grams of HCI (36.46) from reaction of 4.00 g H2SO4 and 393 moles Naci? Round off to 3 significant figures. Do not show unit, g. Do not use scientific notation.

Answer 1

Solution:

Theoretical yield of HCl = 2.98

Explanation:

The balanced reaction is given below:

2 NaCl + 1 H2SO4 -------->  2 HCl + 1 Na2SO4

First, we find out the no of moles of H2SO4 using the formula no of moles = given mass / molar mass

no of moles of H2SO4 = 4 g / (98 g/mol)= 0.0408 moles

now look at the balanced equation 2 NaCl + 1 H2SO4 ------->  2 HCl + 1 Na2SO4 for getting two moles of HCl we need one mole of H2SO4 and 2 moles NaCl but here less no of H2SO4 is there means limiting reagent is H2SO4 so we have to calculate the mass of HCl with respect to limiting agent.

From the balanced equation

1 mol H2SO4 = 2 mol HCl

So, 0.0408 moles H2SO4 = 2 x 0.0408 mol HCl = 0.0816 mol HCl

now weight of HCl = moles of HCl x molar mass of HCl = 0.0816 mol x 36.46 g/mole = 2.975 grams which rounds to 2.98 grams !!!