Question

If a sample of air contain zero. 70 G nitrogen, 0.52G nitrogen, And zero. 13 G carbon dioxide what percentage of the gas is oxygen

Answer 1

7.04% of the sample is oxygen.

Step-by-step explanation:

1st) It is necessary to add all the amounts, since the total amount will represent the 100%:

`0.70g+0.52g+0.13g=1.35g`

Now we know that the 100% of the sample has a total mass of 1.35g.

2nd) Since the oxygen amount is part of the 0.13g of CO2, it is necessary to calculate the grams of oxygen contained in 0.13g of CO2:

- CO2 molar mass: 44g/mol

- O molar mass: 16g/mol

`\begin{gathered} 44gCO_2-32gO \\ 0.13gCO_2-x=(0.13gCO_2*32gO)/(44gCO_2) \\ x=0.095gO \end{gathered}`

Now we know that there are 0.095g of oxygen.

3rd) Finally, we can calculate the percentage of oxygen in the sample, using the total mass (1.35g), the mass of oxygen (0.095g) and a mathematical rule of three:

`\begin{gathered} 1.35g-100\% \\ 0.095g-x=(0.095g*100\%)/(1.35g) \\ x=7.04\% \end{gathered}`

So, 7.04% of the sample is oxygen.