Question

If 21.7 ml of Na, with a density of 0.97 g/mL, react with excess oxygen gas, how many moles of sodium oxide can be formed?

a) 1.95 mol Na2O
b) 1.83 mol Na2O
c) 0.487 mol Na2O
d) 0.458 mol Na2O

Answer 1

To find the number of moles of sodium oxide that can be formed, we need to find the number of moles of sodium and use the balanced chemical equation. The number of moles of sodium can be found by multiplying the volume of sodium by its density and dividing by its molar mass. Then, we multiply the number of moles of sodium by the ratio of moles of sodium oxide to moles of sodium from the balanced equation to find the number of moles of sodium oxide that can be formed.

Step-by-step explanation:

To determine the number of moles of sodium oxide that can be formed, we first need to find the number of moles of sodium. We can do this by multiplying the volume of sodium (21.7 mL) by its density (0.97 g/mL) to find the mass of sodium. Then, we divide the mass of sodium by its molar mass (22.99 g/mol) to find the number of moles of sodium.

Once we have the number of moles of sodium, we can use the balanced chemical equation for the reaction between sodium and oxygen to determine the ratio of moles of sodium to moles of sodium oxide. The balanced equation is:

4Na + O2 -> 2Na2O

From the balanced equation, we can see that 4 moles of sodium react with 1 mole of oxygen to form 2 moles of sodium oxide. So, we multiply the number of moles of sodium by the ratio of moles of sodium oxide to moles of sodium to find the number of moles of sodium oxide that can be formed.