Chemistry question

Question

How man grams of potassium are required to produce 3.64 g of Hydrogen has, H2?

Answer 1

Let us assume you are reacting the potassium (K) with aqueous hydrochloric acid (HCl).

2K(s) + 2HCl(aq) ==> KCl(aq) + H₂(g)

moles of H₂(g) produced = 3.64 g H₂ x 1 mole H₂/2.00 g = 1.82 moles H₂(g)

grams K needed: 1.82 moles H₂(g) x 2 mol K/mol H₂(g) x 39.1 g K/mol K = 142 K needed