Question

A small amount of aluminum reacts with hydrochloric acid (HCl) to form hydrogen gas and aluminum chloride.How many grams of Al are required to produce 0.10 grams of H2?

Answer 1

mass of Al = 0.892 g

Step-by-step explanation

Given:

mass of H2 = 0.10 g

We know the reaction between HCl + Al

`2Al\text{ + 6HCl }\rightarrow2AlCl_3\text{ + 3H}_2`

Required: Mass of Al

Solution:

Step 1: Calculate the moles of H2

n = m/M

n = 0.10g/2.016g.mol

n = 0.0496 mol

Step 2: Use the stoichiometry to find moles of Al

The molar ration between H2 and Al is 3:2

therefore moles of Al = 0.0496 x (2/3) = 0.0331 mol

Step 3: Convert moles of Al to mass

m = n x M

m = 0.0331 mol x 26.98 g.mol

m = 0.892 g