Question

How many molecules of hydrogen gas was produced if
5.0 moles of lead was consumed?

Answer 1

3.01×10²⁴ molecules of H₂

Step-by-step explanation:

Reaction that can produce hydrogen gas from Pb can be this:

Pb + H₂S → PbS + H₂

1 mol of Pb can react to 1 mol of H₂S to produce 1 mol of PbS and 1 mol of H₂

Ratio is always 1:1.

In conclussion 5 moles of lead will produce 5 moles of H₂.

Let's apply the NA to count molecules

1 mol contains 6.02×10²³

Then, 5 moles must contain (5 . 6.02×10²³) = 3.01×10²⁴ molecules