Calculate the mass percent composition of magnesium in Mg(NO3)2. 83.6% 8.92% 27.5% 32.6% 16.4%
The Correct Answer and Explanation is:
To calculate the mass percent composition of magnesium in magnesium nitrate (Mg(NO3)2), follow these steps:
Step 1: Calculate the molar mass of Mg(NO3)2
- The formula for magnesium nitrate is Mg(NO3)2. This means that there is 1 magnesium (Mg) atom, 2 nitrogen (N) atoms, and 6 oxygen (O) atoms in each molecule.
Molar Mass of Mg(NO3)2:
- Magnesium (Mg): 1 × 24.305 g/mol = 24.305 g/mol
- Nitrogen (N): 2 × 14.007 g/mol = 28.014 g/mol
- Oxygen (O): 6 × 16.00 g/mol = 96.00 g/mol
So, the total molar mass of Mg(NO3)2 is:24.305+28.014+96.00=148.319 g/mol24.305 + 28.014 + 96.00 = 148.319 \, \text{g/mol}24.305+28.014+96.00=148.319g/mol
Step 2: Calculate the mass of magnesium
The mass of magnesium in one mole of Mg(NO3)2 is the mass of the magnesium atom, which is:24.305 g/mol24.305 \, \text{g/mol}24.305g/mol
Step 3: Calculate the mass percent composition of magnesium
To find the mass percent of magnesium in Mg(NO3)2, use the formula:Mass percent of magnesium=(Mass of magnesiumMolar mass of Mg(NO3)2)×100\text{Mass percent of magnesium} = \left( \frac{\text{Mass of magnesium}}{\text{Molar mass of Mg(NO3)2}} \right) \times 100Mass percent of magnesium=(Molar mass of Mg(NO3)2Mass of magnesium)×100
Substitute the known values:Mass percent of magnesium=(24.305148.319)×100=16.4%\text{Mass percent of magnesium} = \left( \frac{24.305}{148.319} \right) \times 100 = 16.4\%Mass percent of magnesium=(148.31924.305)×100=16.4%
Conclusion:
The mass percent composition of magnesium in Mg(NO3)2 is 16.4%.
