What is the molar mass of K2SO4?
Understand the Problem
The question is asking for the molar mass of the compound potassium sulfate (K2SO4). To calculate this, we will sum the atomic masses of all the atoms present in the formula: 2 potassium (K), 1 sulfur (S), and 4 oxygen (O) atoms.
Answer
The molar mass of K2SO4 is $174.27 \, \text{g/mol}$.
Answer for screen readers
The molar mass of potassium sulfate (K2SO4) is $174.27 , \text{g/mol}$.
Steps to Solve
 Identify atomic masses First, we need to know the atomic masses of the elements in potassium sulfate (K2SO4):
 Potassium (K): approximately 39.10 g/mol
 Sulfur (S): approximately 32.07 g/mol
 Oxygen (O): approximately 16.00 g/mol

Calculate the contribution from potassium Since there are 2 potassium atoms in the compound, we calculate the total mass contributed by potassium: $$ \text{Mass from K} = 2 \times 39.10 , \text{g/mol} = 78.20 , \text{g/mol} $$

Calculate the contribution from sulfur There is 1 sulfur atom in the compound, so its total mass is: $$ \text{Mass from S} = 1 \times 32.07 , \text{g/mol} = 32.07 , \text{g/mol} $$

Calculate the contribution from oxygen There are 4 oxygen atoms in the compound, so we calculate the total mass from oxygen: $$ \text{Mass from O} = 4 \times 16.00 , \text{g/mol} = 64.00 , \text{g/mol} $$

Sum all contributions Now, we add up the contributions from potassium, sulfur, and oxygen to get the total molar mass of K2SO4: $$ \text{Molar Mass of K2SO4} = 78.20 , \text{g/mol} + 32.07 , \text{g/mol} + 64.00 , \text{g/mol} = 174.27 , \text{g/mol} $$
The molar mass of potassium sulfate (K2SO4) is $174.27 , \text{g/mol}$.
More Information
Potassium sulfate is commonly used as a fertilizer in agriculture. Its molar mass is important for stoichiometric calculations in chemical reactions involving this compound.
Tips
 Forgetting to multiply the atomic mass by the number of atoms for each element can lead to incorrect results.
 Not using the correct atomic masses based on periodic table values.