Question

How many moles are present in 2.5 grams of N2?

a) 0.089 moles
b) 0.18 moles
c) 1.3 moles
d) 11 moles

Answer 1

The number of moles present in 2.5 grams of N2 gas is 0.089 moles, calculated by dividing the mass by the molar mass of N2 (28.02 g/mol).

Step-by-step explanation:

To answer the question 'How many moles are present in 2.5 grams of N2?', we will use the molar mass of nitrogen gas (N2) and the given mass to calculate the number of moles. Nitrogen gas is diatomic, meaning that each molecule is made up of two nitrogen atoms. The atomic weight of a single nitrogen atom is approximately 14.01 grams per mole, so for N2, which has two such atoms, the molar mass is 2 x 14.01 or about 28.02 grams per mole.

To find the number of moles, we do the following calculation:

1. Divide the mass of the N2 gas by its molar mass:
   Number of moles = mass / molar mass = 2.5 g / 28.02 g/mol
2. Complete the division:
   Number of moles = 0.089 moles (approximately)

Therefore, the correct answer is a) 0.089 moles.