Questions: 3. How many grams of oxygen are there in 9.5 g of NaNO 3 ? A) 3.67 g B) 5.37 g C) 4.50 g D) 6.00 g

Solution Steps

First, we need to calculate the molar mass of sodium nitrate (NaNO\(_3\)):

• Sodium (Na): \(22.99 \, \text{g/mol}\)
• Nitrogen (N): \(14.01 \, \text{g/mol}\)
• Oxygen (O): \(16.00 \, \text{g/mol}\) (3 atoms of oxygen)

\[ \text{Molar mass of NaNO}_3 = 22.99 + 14.01 + (3 \times 16.00) = 85.00 \, \text{g/mol} \]

Next, we find the mass fraction of oxygen in NaNO\(_3\):

\[ \text{Mass of oxygen in NaNO}_3 = 3 \times 16.00 = 48.00 \, \text{g} \]

\[ \text{Mass fraction of oxygen} = \frac{48.00}{85.00} \approx 0.5647 \]

Now, we use the mass fraction to find the mass of oxygen in 9.5 g of NaNO\(_3\):

\[ \text{Mass of oxygen} = 9.5 \, \text{g} \times 0.5647 \approx 5.3647 \, \text{g} \]

Rounding to four significant digits:

\[ \text{Mass of oxygen} \approx 5.365 \, \text{g} \]

Final Answer