What Is The Molar Mass Of Potassium Nitrate (KNO3)? O 29.0 G/Mol 180 G/Mol O 101 G/Mol O 210 G/Mol 85.1 G/Mol
The correct answer and explanation is:
The molar mass of potassium nitrate (KNO₃) is 101 g/mol.
Explanation:
To calculate the molar mass of potassium nitrate (KNO₃), we sum the molar masses of each element in the compound. These values are obtained from the periodic table:
- Potassium (K):
The atomic mass of potassium is approximately 39.1 g/mol. - Nitrogen (N):
The atomic mass of nitrogen is approximately 14.0 g/mol. - Oxygen (O):
The atomic mass of oxygen is approximately 16.0 g/mol. Since KNO₃ has three oxygen atoms, the contribution from oxygen is:
16.0 g/mol×3=48.0 g/mol16.0 \, \text{g/mol} \times 3 = 48.0 \, \text{g/mol}.
Now, sum the contributions: 39.1 g/mol (K)+14.0 g/mol (N)+48.0 g/mol (O)=101.1 g/mol.39.1 \, \text{g/mol} \, (\text{K}) + 14.0 \, \text{g/mol} \, (\text{N}) + 48.0 \, \text{g/mol} \, (\text{O}) = 101.1 \, \text{g/mol}.
Thus, the molar mass of potassium nitrate is 101 g/mol (rounded to three significant figures).
Why is molar mass important?
- Chemical Calculations:
The molar mass allows chemists to convert between the mass of a substance and the number of moles. For instance, if you have 101 grams of KNO₃, you know it represents exactly 1 mole of the substance. - Reactions and Stoichiometry:
Molar mass is critical for determining the proportions of reactants and products in chemical reactions. For example, when KNO₃ decomposes, its molar mass helps calculate the amounts of resultant products like oxygen gas. - Practical Applications:
Potassium nitrate is commonly used in fertilizers, food preservation, and pyrotechnics. Knowing its molar mass ensures precise formulations in these applications.
By understanding the molar mass, you can apply this knowledge to solve problems in chemistry, from laboratory experiments to industrial processes.