Answer:
A. 5.9%
Step-by-step explanation:
To determine the percent by mass of hydrogen in NH, we need to calculate the mass of hydrogen in one mole of NH and then express it as a percentage of the formula mass.
The formula mass of NH is given as 17.0 g/mol.
The molar mass of hydrogen (H) is approximately 1.01 g/mol.
In one mole of NH, there is 1 mole of hydrogen.
Therefore, the mass of hydrogen in one mole of NH is 1.01 g/mol.
To calculate the percent by mass of hydrogen, we divide the mass of hydrogen by the formula mass of NH and multiply by 100:
Percent by mass of hydrogen = (mass of hydrogen / formula mass of NH) * 100
Percent by mass of hydrogen = (1.01 g/mol / 17.0 g/mol) * 100
Percent by mass of hydrogen ≈ 5.94%
Therefore, the percent by mass of hydrogen in NH is approximately 5.94%. Rounding to the nearest tenth, the answer is approximately 5.9%. Thus, the correct answer is A. 5.9%.