Answer to Question #190017 in General Chemistry for Tyler Drotning

Question

Calculate the moles of potassium sulfide formed when 5.4 g of potassium gas reacts with excess sulfur.

2 K+S > K2S

Answer 1

M(K) = 39.1 g/mol

$n(K) = \frac{m}{M} = \frac{5.4}{39.1}= 0.138 \;mol$

According to the reaction:

n(K₂S) $= \frac{1}{2}n(K) = \frac{1}{2} \times 0.138 = 0.069 \;mol$

Answer: 0.069 mol