2 Consider the reaction represented by the unbalanced equati

2. Consider the reaction represented by the (unbalanced) equation: Mg(s) + HCl(a) MgCl,(aq)+ H2(g) Determine the mass of H,(g) that can be produced from the following: a. 10.0 g Mg(s) reacts completely with HCl(aq). b. 20.0 g HCI (aq) reacts completely with Mg(s). The mass of oxygen gas that would be needed to completely react with 10.0 g of hydrogen gas to form water is instead reacted completely with methane (CH) to form carbon dioxide and water. Determine the mass of carbon dioxide produced. 3.

Solution

The balanced reaction will be

Mg + 2HCl = MgCl₂ + H₂

molar mass of Mg = 24.3g

molar mass of HCl = 36.5g

molar mass of H₂ = 2g

molar mass of MgCl₂ = 95.2g

As the reaction proceeds 1 mole Mg reacts with 2 mole HCl to give 1mole MgCl₂ and 1 mole H₂

So,

(a)No. of moles in 10 g 0f Mg = 10/12 =0.83 which completely reacts with 2 times HCl to produce 1 times H₂ i.e- 0.83 mole of H₂

Hygrogen molecule produced = 0.83 * 2g = 1.67g

(b) No of moles for 20 g HCl = 20 / 36.5 = 0.55 mole

It will give half of the molar molar amount of HCl i.e = 0.275 mole

So , mass of H₂ produce = 0.275 * 2 = 0.55g