Question

Pls help me I don’t know how to do this asap help

Answer 1

`17.65\text{ \%}`

Step-by-step explanation:

Here, we want to get the percentage by mass of the water molecules in the given compound

To get this, we have to divide the molar mass of water by the molar mass of the percentage and write the answer as a percentage

The molar mass of water is 18 g/mol

The molar mass of MgCO3 is 84 g/mol

Thus, the percentage by mass of water will be:

`\frac{18}{18\text{ + 84}}\text{ }*\text{ 100 \% = 17.65 \%}`