Calculating Molarity of Water

Molarity is defined as the amount of a substance in moles per unit volume of solution. In order to calculate the molarity of water, we need to know the amount of water in grams and the molar mass of water.

Formula for Calculating Molarity

The formula for calculating molarity is:

Molarity (M) = moles of solute / liters of solution

Step-by-Step Calculation

Here are the steps to calculate the molarity of 900 g of water:

1. Convert grams of water to liters of water:

Density of water = 1 g/mL

900 g = 900 mL = 0.9 L

2. Calculate the number of moles of water:

Molar mass of water = 18 g/mol

Moles of water = mass of water / molar mass of water

Moles of water = 0.9 L x 1000 mL/L x 1 g/mL / 18 g/mol

Moles of water = 50 mol

3. Calculate the molarity of water:

Molarity of water = moles of water / liters of water

Molarity of water = 50 mol / 0.9 L

Molarity of water = 55.56 M

Therefore, the molarity of 900 g of water is 55.56 M.

Conclusion

Molarity is a measure of the concentration of a solution. To calculate the molarity of water, we need to know the amount of water in grams and the molar mass of water. Using the formula for molarity, we can calculate the molarity of water in moles per liter.