To find out how many grams of lithium hydroxide are present when you have 3 moles, you first need to know the molar mass of LiOH.
The molar mass of lithium hydroxide can be calculated by adding the atomic masses of lithium (Li), oxygen (O), and hydrogen (H):
- Lithium (Li): approximately 6.94 g/mol
- Oxygen (O): approximately 16.00 g/mol
- Hydrogen (H): approximately 1.01 g/mol
Now, let’s add these together:
Molar mass of LiOH = 6.94 g/mol + 16.00 g/mol + 1.01 g/mol = 23.95 g/mol
Now that we know the molar mass, we can calculate the total grams in 3 moles:
Total grams = number of moles × molar mass = 3 moles × 23.95 g/mol = 71.85 g
Rounding this to the nearest whole number, we get approximately 72 g.
So the correct answer is d) 72 g.