What is the molar mass of K2SO4 ? Use at least four significant figures. Just type the number: _ g/mol Hint: You must add up the masses of two potassium atoms, one sulfur atom, and four oxygen atoms from the periodic table.
The Correct Answer and Explanation is:
The molar mass of K2SO4 is calculated by adding the molar masses of the individual atoms:
- Potassium (K): The atomic mass of potassium is approximately 39.10 g/mol.
Since there are two potassium atoms in K2SO4, the total mass from potassium is:
2×39.10=78.20 g/mol2 \times 39.10 = 78.20 \, \text{g/mol}2×39.10=78.20g/mol - Sulfur (S): The atomic mass of sulfur is approximately 32.07 g/mol.
- Oxygen (O): The atomic mass of oxygen is approximately 16.00 g/mol.
Since there are four oxygen atoms in K2SO4, the total mass from oxygen is:
4×16.00=64.00 g/mol4 \times 16.00 = 64.00 \, \text{g/mol}4×16.00=64.00g/mol
Now, we add up all the masses:78.20+32.07+64.00=174.27 g/mol78.20 + 32.07 + 64.00 = 174.27 \, \text{g/mol}78.20+32.07+64.00=174.27g/mol
Thus, the molar mass of K2SO4 is 174.27 g/mol.
This value is based on the atomic masses from the periodic table, rounded to four significant figures. When calculating molar mass, each atomic contribution is weighted by the number of atoms in the compound. For instance, potassium contributes 78.20 g/mol, sulfur contributes 32.07 g/mol, and oxygen contributes 64.00 g/mol, all of which add up to the total molar mass of K2SO4.
