Question

one mole of ammonia, nh3, is made up one atom of nitrogen and three atoms of hydrogen.
true
false
how many molecules of methane (ch₄) are in 0.500 moles of methane?
6.02×10²³ molecules
1.20×10²⁴ molecules
3.01×10²³ molecules
16.0 molecules

Explanation:

First Question (True/False about NH₃ composition)

A molecule of NH₃ (ammonia) has 1 N atom and 3 H atoms. One mole of NH₃ contains Avogadro's number of NH₃ molecules, but the statement is about the composition of one mole (in terms of atoms per molecule, which scales with moles). So the statement is True as the molecular formula shows 1 N and 3 H per NH₃ unit, and a mole of NH₃ has that atomic ratio.

Step1: Recall Avogadro's Number

Avogadro's number is \( N_A = 6.02 \times 10^{23} \) molecules/mol (number of particles per mole).

Step2: Use Moles to Molecules Formula

The formula to find number of molecules (\( N \)) is \( N = n \times N_A \), where \( n \) is moles.
Here, \( n = 0.500 \) mol, \( N_A = 6.02 \times 10^{23} \) molecules/mol.

Step3: Calculate

\( N = 0.500 \, \text{mol} \times 6.02 \times 10^{23} \, \text{molecules/mol} = 3.01 \times 10^{23} \, \text{molecules} \)

Answer:

True

Second Question (Molecules in 0.500 moles of CH₄)