The hardness of a sample of water is 75 ppm. Assuming that water conta...
Calculation of the mass of MgSO4 in a water sample:
Given:
Hardness of water = 75 ppm
Assumption: Water contains only MgSO4
To determine the mass of MgSO4 in the water sample, we need to consider the molar mass of MgSO4 and convert ppm to mass.
1. Molar Mass of MgSO4:
The molar mass of MgSO4 can be calculated by adding the atomic masses of its constituent elements:
Mg (magnesium) = 24.31 g/mol
S (sulfur) = 32.07 g/mol
O (oxygen) = 16.00 g/mol
Molar mass of MgSO4 = (1 × Mg) + (1 × S) + (4 × O)
= (1 × 24.31 g/mol) + (1 × 32.07 g/mol) + (4 × 16.00 g/mol)
= 24.31 g/mol + 32.07 g/mol + 64.00 g/mol
= 120.38 g/mol
Therefore, the molar mass of MgSO4 is 120.38 g/mol.
2. Conversion from ppm to mass:
Parts per million (ppm) is a unit of concentration used to express the ratio of the mass of a substance to the total mass of the solution, multiplied by 10^6.
To convert ppm to mass, we need the total mass of the solution. In this case, we are given that the water sample weighs 10 kg (or 10,000 g).
The ppm value represents the mass of the solute (MgSO4) in 1 million parts of the solution (water).
Given that the hardness of the water sample is 75 ppm, we can calculate the mass of MgSO4 in the water sample using the following formula:
Mass of MgSO4 = (ppm value × total mass of solution) / 10^6
Mass of MgSO4 = (75 ppm × 10,000 g) / 10^6
= (75 × 10,000) / 10^6
= 750,000 / 10^6
= 0.75 g
Therefore, the mass of MgSO4 in the 10 kg water sample is 0.75 g.
Explanation:
The hardness of water is a measure of the concentration of dissolved minerals, mainly calcium and magnesium salts. In this case, we assume that water contains only MgSO4 (magnesium sulfate) to calculate the mass.
First, we calculate the molar mass of MgSO4 by summing the atomic masses of magnesium, sulfur, and oxygen. The molar mass of MgSO4 is found to be 120.38 g/mol.
Next, we convert the given ppm value (75 ppm) to mass by multiplying it with the total mass of the solution (10,000 g) and dividing by 10^6. This gives us the mass of MgSO4 in grams.
The final result shows that the mass of MgSO4 in the 10 kg water sample is 0.75 g.
The hardness of a sample of water is 75 ppm. Assuming that water conta...
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