Write the balanced equation for the synthesis of hydrochloric acid. How many moles of chlorine are required for the production of 72.92 g hydrochloric acid?

a. H₂(g) + Cl₂(g) ⇒ 2HCl (g)

HCl (g) + H₂O (l) ⇒ H₃O⁺ (aq) + Cl⁻ (aq)

b. 0.999 mol

Explanation:

a. Write the balanced equation for the synthesis of hydrochloric acid.  

The balanced equation for the synthesis of hydrochloric acid is thus

H₂(g) + Cl₂(g) ⇒ 2HCl (g)

HCl (g) + H₂O (l) ⇒ H₃O⁺ (aq) + Cl⁻ (aq)

b.  How many moles of chlorine are  required for the production of 72.92 g hydrochloric acid?

We need to find the number of moles of HCl contained in 72.92 g. So, molar mass M of HCl = molar mass of hydrogen + molar mass of chlorine

molar mass of hydrogen = 1 g/mol

molar mass of chlorine = 35.5 g/mol

So, molar mass of HCl = 1 g/mol + 35.5 g/mol = 36.5 g/mol.

We now find the number of moles n of HCl in 72.92 g from n = m/M where m = mass of HCl = 72.92 g

n = 72.92 g/36.5 g/mol = 1.998 mol.

From the balanced chemical equation, 1 mol of chlorine atoms produces 2 moles of hydrogen chloride gas. Therefore, the number of moles of chlorine atoms produces 1.998 mol HCl or 72.92 g HCl is 1 mol × 1.998 mol/2 mol = 0.999 mol

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.