select all that apply. at stp conditions, 0.25 moles of co₂(g), h₂(g), nh₃(g): will occupy the same volume…

select all that apply. at stp conditions, 0.25 moles of co₂(g), h₂(g), nh₃(g): will occupy the same volume will have the same g.f.w. will contain the same number of atoms will contain the same number of molecules

select all that apply. at stp conditions, 0.25 moles of co₂(g), h₂(g), nh₃(g): will occupy the same volume will have the same g.f.w. will contain the same number of atoms will contain the same number of molecules

Answer

Answer:

  • will occupy the same volume
  • will contain the same number of molecules

Explanation:

Step1: Recall Avogadro's law

At STP, equal moles of any gas occupy the same volume. Since we have 0.25 moles of each gas ($CO_2$, $H_2$, $NH_3$), they will occupy the same volume. The molar volume at STP is 22.4 L/mol for any ideal - gas, and these can be approximated as ideal gases under STP conditions.

Step2: Analyze gram - formula weight (g.f.w)

The gram - formula weight of $CO_2$ is $12 + 2\times16=44$ g/mol, for $H_2$ is $2\times1 = 2$ g/mol, and for $NH_3$ is $14+3\times1 = 17$ g/mol. So, they do not have the same g.f.w.

Step3: Analyze number of atoms

1 molecule of $CO_2$ has 3 atoms, 1 molecule of $H_2$ has 2 atoms, and 1 molecule of $NH_3$ has 4 atoms. Although the number of moles is the same, the number of atoms per molecule is different, so the total number of atoms is different.

Step4: Analyze number of molecules

According to Avogadro's number ($N = n\times N_A$), where $n$ is the number of moles and $N_A$ is Avogadro's number ($6.022\times10^{23}$ molecules/mol). Since $n = 0.25$ mol for each gas, the number of molecules for each gas is $n\times N_A=0.25\times6.022\times10^{23}$ molecules. So, they contain the same number of molecules.