Answer :
Final answer:
To calculate the mass for 1.55 moles of nitrogen trichloride, the molar mass of NCl3 is found to be 120.36 g/mol. Multiplying this by 1.55 moles gives 186.56 grams, which rounds to 187 grams.
Explanation:
To calculate the mass in grams of 1.55 moles of nitrogen trichloride (NCl3), we need to determine the molar mass of the compound. The molar mass is the sum of the mass of one mole of nitrogen (N) and three moles of chlorine (Cl). Using the periodic table, the molar mass of nitrogen is approximately 14.01 grams/mol and chlorine is approximately 35.45 grams/mol.
Therefore, the molar mass of NCl3 is calculated as:
- Molar mass of N = 14.01 g/mol
- Molar mass of Cl = 35.45 g/mol × 3 = 106.35 g/mol
- Total molar mass of NCl3 = 14.01 g/mol + 106.35 g/mol = 120.36 g/mol
To find the mass of 1.55 moles of NCl3, we multiply the number of moles by the molar mass:
1.55 moles × 120.36 g/mol = 186.56 grams
Therefore, to obtain 1.55 moles of nitrogen trichloride, 187 grams should be measured out (rounding to the nearest whole number).
1.55 moles of NCl3 is approximately 187 grams. Option C is the correct choice for the measurement.
To find the mass of nitrogen trichloride (NCl3) when you have 1.55 moles, you can use the molar mass of NCl3, which is the sum of the atomic masses of nitrogen (N) and three times the atomic mass of chlorine (Cl).
The atomic mass of N = 14.01 g/mol
The atomic mass of Cl = 35.45 g/mol
So, the molar mass of NCl3 = 14.01 + 3 * 35.45 = 120.36 g/mol (approximately)
Now, you can use the formula:
Mass = Number of moles × Molar mass
Mass = 1.55 moles × 120.36 g/mol ≈ 186.798 g
The closest option is C. 187 g.
The complete question is here:
If you want 1.55 moles of nitrogen trichloride, how many grams should you measure out?
A. 9.33 g
B. 0.0129 g
C. 187 g
E. 120. g
