Question

How many moles of sodium (^{Na}) would be needed to react with 5.0 moles of oxygen (^{O2}) in the balanced chemical equation: 4^{Na} + ^{O2} → 2^{Na2O}?

A) 10.0 moles of sodium
B) 20.0 moles of sodium
C) 2.5 moles of sodium
D) 5.0 moles of sodium

Answer 1

According to the balanced chemical equation (4Na + O2 → 2Na2O), 4 moles of sodium are required for every mole of oxygen. For 5.0 moles of oxygen, 20.0 moles of sodium are needed.

Step-by-step explanation:

To find out how many moles of sodium (Na) are required to react with 5.0 moles of oxygen (O2) according to the balanced chemical equation 4Na + O2 → 2Na2O, you need to use stoichiometry. In this equation, for every 1 mole of O2, 4 moles of Na are required. Since the question provides us with 5.0 moles of O2, we need to multiply the amount of O2 by the stoichiometric coefficient for Na in the equation, which is 4.

So, the calculation would be:

5.0 moles O2 x (4 moles Na / 1 mole O2) = 20.0 moles of sodium.

Therefore, the correct answer is B) 20.0 moles of sodium.