Calculate the mass of sodium oxide (Na2O) that can be made by completely burning 5.0g of sodium (Na) in oxygen. Give your answer to 3 significant figures

To solve this problem, we need to use the concept of stoichiometry, which is a section of chemistry that involves using relationships between reactants and/or products in a chemical reaction to determine desired quantitative data.

Here are the steps:

1. Write down the balanced chemical equation for the reaction. Sodium (Na) reacts with oxygen (O2) to form sodium oxide (Na2O). The balanced equation is: 4Na + O2 → 2Na2O

2. Calculate the molar mass of sodium (Na) and sodium oxide (Na2O). The atomic mass of sodium (Na) is approximately 23 g/mol. Therefore, the molar mass of sodium (Na) is 23 g/mol. The molar mass of sodium oxide (Na2O) is (2*23) + 16 = 62 g/mol.

3. Determine the number of moles of sodium (Na) in 5.0g. We use the formula: moles = mass / molar mass moles of Na = 5.0g / 23 g/mol = 0.217 mol

4. From the balanced chemical equation, we can see that the mole ratio of Na to Na2O is 4:2 or 2:1. This means that for every 2 moles of sodium (Na) that react, 1 mole of sodium oxide (Na2O) is produced. Therefore, the number of moles of Na2O that can be produced from 0.217 mol of Na is 0.217/2 = 0.1085 mol.

5. Finally, we can find the mass of sodium oxide (Na2O) that can be produced by multiplying the number of moles by the molar mass. mass = moles * molar mass mass of Na2O = 0.1085 mol * 62 g/mol = 6.73 g

So, the mass of sodium oxide (Na2O) that can be made by completely burning 5.0g of sodium (Na) in oxygen is approximately 6.73 g to three significant figures.