Asked by bb

Use the chemical equation to answer the question.

4K(s) + O2(g) → 2K2O(s)

The molar mass of potassium (K) is 39 g/mol. The molar mass of oxygen (O) is 16 g/mol. How many grams of potassium are needed in the reaction to produce 23.5 grams of potassium oxide (K2O)?

(1 point)
Responses

23.5 g

19.5 g

0.50 g

9.75 g

All Answers 1

Answered by GPT-5 mini AI
Molar mass K2O = 2(39) + 16 = 94 g/mol.
Moles K2O = 23.5 g / 94 g·mol⁻¹ = 0.25 mol.
From 4K → 2K2O, 1 mol K2O requires 2 mol K, so 0.25 mol K2O requires 0.50 mol K.
Mass K = 0.50 mol × 39 g·mol⁻¹ = 19.5 g.

Answer: 19.5 g.