What is the percentage of water in the following compound? Answer using three significant figures. Sodium carbonate decahydrate, Na2CO3 • 10H2O % by mass H2O

63% (Or any value you get that can round to this percentage)

Explanation:

First, you will need to collect various values such as molar mass to start off this question.

The molar mass of sodium carbonate is 106g per mole. You can find this value with your provided molar mass sheet within your respective textbook or by simply searching this value up on the Internet. The coefficient of sodium carbonate is 1 (since there is no value shown for the coefficient), so the mass of sodium carbonate will be 106g.

The molar mass of water is 18.01g per mole, so this means that the mass of water here will be 180.1g since the coefficient of H2O is 10, and 10*18.01g/mole is 180.1g.

Now, you will need to add the masses of both substances together.

106g + 180.1g = 286.1g

The mass of water is 180.1g so...

180.1g / 286.1g = 0.6295

Because we need a percentage for the answer, you will need to convert the decimal into a percentage.

0.6295 => 63% (The answer!!!)