Question

Give the equation: 2K + 2H2O --> 2KOH + H2 If 23.5 grams of potassium are reacted with excess water, how many grams of Hydrogen will be formed? Question 3 options: 0.337g H2 0.5608g H2 0.3909g H2 0.6011g H2

Answer 1

Answers:

0.606 g H₂

Step-by-step explanation:

We know we will need a balanced equation with masses and molar masses, so let’s gather all the information in one place.  

M_r:   39.10                            2.016

           2K + 2H₂O ⟶ 2KOH + H₂

m/g:   23.5

(a) Calculate the moles of K

n = 23.5 g K × 1 mol K /39.10 g K

n = 0.6010 mol K

(b) Calculate the moles of H₂

The molar ratio is (1 mol H₂/2 mol K)

n = 0.6010 mol K × (1 mol H₂/2 mol K)

n = 0.3005 mol H₂

(c) Calculate the mass of H₂

m = 0.3005 mol H₂ × (2.016 g H₂/1 mol H₂)

m = 0.606 g H₂