Question

1. How many molecules are in 96.1 g of carbon dioxide?2. How many oxygen atoms are in 96.1 g of CO2?3. How many grams would 1.0 x 10^25 particles of copper(II) sulfate weigh?4. How many liters of H2 gas are equal to 4374.4 grams of H2 gas?

Answer 1

To calculate the number of molecules we can apply the Avogadro equation, which relates the moles of a compound to the number of molecules. The Avogadro number tells us that in one mole of any substance there are 6.022x10^23 molecules.

`1mo_{}l=6.022*10^(23)molecules`

Now we must calculate the number of moles in the mass we are given. For this, we use the molar mass.

The molar mass of CO2 is 44.01 g/mol, so the moles of CO2 in 96.1 g will be:

`\begin{gathered} Mo_{}lCO_2=\frac{\text{Mass of CO}_2}{Molar\text{ mass}} \\ Mo_{}lCO_2=(96.1g)/(44.01(g)/(mol)) \\ Mo_{}lCO_2=2.18\text{mol} \end{gathered}`

Now we will apply Avogadro to know the number of molecules present in 2.18 moles of CO2.

`\begin{gathered} \text{Number of molecules=2.18mol}*(6.022*10^(23)molecules)/(1mol) \\ \text{Number of molecules}=1.31*10^(24)molecules \end{gathered}`

So, in 96.1 g of carbon dioxide, there are 1.31x10^24 molecules