Questions: Chapter 7 Question 46 - Multiple Choice Part A 3.00 moles of NO2 have a mass of 46.0 g. 30.0 g. 138 g. 45.0 g. 90.0 g.

Solution Steps

To find the mass of 3.00 moles of \(\mathrm{NO}_2\), we first need to determine the molar mass of \(\mathrm{NO}_2\). The molar mass is calculated by adding the atomic masses of nitrogen (N) and oxygen (O) in the compound:

• Atomic mass of nitrogen (N) = 14.01 g/mol
• Atomic mass of oxygen (O) = 16.00 g/mol

Since \(\mathrm{NO}_2\) contains one nitrogen atom and two oxygen atoms, its molar mass is:

\[ \text{Molar mass of } \mathrm{NO}_2 = 14.01 + 2 \times 16.00 = 46.01 \, \text{g/mol} \]

Now, we use the molar mass to calculate the mass of 3.00 moles of \(\mathrm{NO}_2\):

\[ \text{Mass} = \text{Number of moles} \times \text{Molar mass} = 3.00 \, \text{moles} \times 46.01 \, \text{g/mol} = 138.03 \, \text{g} \]

Final Answer