Answer:
carbonate has a mass of 4.56g. After heating, the anhydrous salt that remains has a mass of 3.12g. Determine the correct formula and name of the hydrate.
1. To determine the formula and name of the hydrate, we need to find the mass of water that was originally present in the sample.
Mass of CuSO4 before heating = 3.97g
Mass of CuSO4 after heating = 2.54g
Mass of water lost = 3.97g - 2.54g = 1.43g
To find the number of moles of CuSO4 and water, we use their respective molar masses:
Molar mass of CuSO4 = 63.55g/mol
Molar mass of H2O = 18.015g/mol
Moles of CuSO4 = 2.54g / 63.55g/mol = 0.04 mol
Moles of H2O = 1.43g / 18.015g/mol = 0.079 mol
Next, we divide the moles of CuSO4 and H2O by the smallest number of moles to obtain the simplest, whole-number ratio of the two:
CuSO4 : H2O = 0.04/0.04 : 0.079/0.04 = 1 : 1.98 (rounded to 2)
Therefore, the formula of the hydrate is CuSO4 · 2H2O, and the name is copper(II) sulfate dihydrate.
To find the formula of the hydrate, we need to determine the mass of the anhydrous salt (without water).
Mass of hydrate = 8.85g
Mass of anhydrous salt = 8.85g - 1.28g = 7.57g
The formula of the hydrate can be determined by calculating the ratio of moles of anhydrous salt to moles of water.
Moles of anhydrous salt = 7.57g / 106g/mol = 0.0713 mol
Moles of water lost = 1.28g / 18g/mol = 0.0711 mol
The ratio of moles is approximately 1:1, suggesting that the formula of the hydrate is Na2CO3·H2O.
The name of the hydrate is sodium carbonate monohydrate.