What is the mass of 91.4 moles of NH3 molecules?

Question

BlackTom AI · Accepted Answer

We are given a question about the mass corresponding to a certain amount of NH3 molecules expressed in moles and asked to select the correct numerical mass value from the options.

Option A: 2.58 × 10–21 g. This is extraordinarily small for 91.4 moles. To put it in perspective, even a single molecule has a mass on the order of 10^−23 g, so 91.4 moles (which contains on the order of 6.02×10^23 × 91.4 molecules) would not yield such a tiny mass. This option is inconsistent with the mole-to-gram conversion using molar mass, so it is incorrect.

Option B: 9.37 × 10^26 g. This is an astronomically large mass far exceeding any practical chemical quantity for a few tens of moles. The mass of a few dozen moles cannot approach 10^27 g (which is about the mass of something on a planetary scale), so this option is also incorrect.

Option C: 5.37 g. This is far smaller than the expected mass for 91.4 moles of NH3. Since the molar mass of NH3 is about 17 g per mole, 91.4 moles should weigh roughly 91.4 × 17 ≈ 1550 g. Therefore, this option underestimates the mass by about three orders of magnitude and is incorrect.

Option D: 1.56 × 10^3 g. This is the mass you would obtain by converting moles to grams using the molar mass. Using NH3 molar mass ≈ 17.034 g/mol, the mass is 91.4 mol × 17.034 g/mol ≈ 1557 g, which is about 1.56 × 10^3 g. This aligns with the standard mole-to-mass calculation for NH3 and is therefore consistent with the data given.

Option E: 17.03 g. This number matches the molar mass of NH3, not the total mass of 91.4 moles. It would be the mass of a single mole of NH3, not of 91.4 moles, so this option is incorrect for the question as stated.

In summary, options A, B, C, and E fail to reflect the correct application of molar mass to moles for the total mass of 91.4 moles, while option D provides the correct total mass when the molar mass is multiplied by the amount in moles. The calculation steps rely on using NH3 molar mass ≈ 17.034 g/mol and total mass = (moles) × (molar mass).

What is the mass of 91.4 moles of NH3 molecules?

View Explanation

Log in for full answers

Similar Questions

Which sample will have the greatest mass?

The molar mass for H is 1 and for He is 4. What is the ratio of the molar mass of He to that of H2?

Find the molar mass of ethanol, C 2 H 6 O C 2 H 6 O . BlackTom题目解析

Q13 V20.0438 mol of an organic compound has a mass of 1.84 g. The compound is likely to be an:

Which of the following has the lowest mass?

3.0 g of a gas occupies the same volume as 1.0 g of methane gas, CH4, at the same temperature and pressure. The gas could be: [ Molar Masses (g mol-1) C = 12.0 H = 1.00 O = 16.0 N =14.0 ]

The mass of one mole of nitrogen gas is 28.0 g.

The molar mass of copper(II) sulfate, CuSO4, is 63.6 g.

More Practical Tools for International Students

Homework AI Solver

Stylized Writing Assistant

Plagiarism Checker Assistant

Citation Assistant

In-Class Translation Assistant

Class Notes Assistant

Quiz Search Assistant

Past Exam Questions by School

Smart Practice Assistant

Adaptive Practice

Making Your Study Simpler