Question

Zn + 2HCI → ZnCl2 + Hz

3. How many moles of hydrogen, H2, will be produced if 0.95 moles of zinc, Zn, reacts
with 6.2 moles of HCI? (Hint: Must determine limiting reactant.)

Answer 1

0.95 moles

Step-by-step explanation:

I believe that this is the equation we are looking at since this is an acid- metal reaction, thus the products would be a salt and hydrogen gas (H₂):

Zn +2HCl → ZnCl₂ +H₂

The limiting reactant is the reactant that we do not have enough of for the reaction to continue. From the balanced equation, the mole ratio of Zn to HCl is 1: 2. This means that for every 1 mole of Zn, 2 moles of HCl is needed.

Let's calculate the number of moles of HCl needed to react with 0.95 moles of Zn.

Number of moles of HCl required

= 0.95 ×2

= 1.9 moles

Since we have 6.2 moles of HCl, HCl is in excess and thus Zn is the limiting reactant. For 6.2 moles of HCl, 3.1 moles of Zn would be needed but we only have 0.95 moles.

For every 1 mole of Zn, 1 mole of H₂ is produced.

Thus, since 0.95 moles of Zn has reacted,

number of moles of H₂ produced= 0.95 moles