Final answer:
To find the empirical formula for the oxide of tin, subtract the masses of the containers to find the mass of tin and the gained mass of oxygen, then convert to moles and find the smallest whole-number ratio, which approximates to SnO2.
Step-by-step explanation:
Calculating the Empirical Formula for Tin Oxide
First, we need to find the mass of tin that reacted and the mass of oxygen that combined with it during the heating process. The mass of the tin sample is obtained by subtracting the mass of the empty crucible with cover (19.66 g) from the mass of the crucible, cover, and tin sample (21.76 g), which gives us 2.10 g of tin. After heating, the increase in mass indicates the amount of oxygen that reacted with the tin. This is calculated by subtracting the mass of the crucible, cover, and tin sample before heating (21.76 g) from the mass after heating (22.29 g), yielding 0.53 g of oxygen.
Next, we convert these masses to moles by dividing by their respective atomic masses. Tin has an atomic mass of approximately 118.71 g/mol and oxygen has an atomic mass of about 16.00 g/mol:
- Moles of tin: 2.10 g / 118.71 g/mol = 0.0177 mol
- Moles of oxygen: 0.53 g / 16.00 g/mol = 0.0331 mol
To find the smallest whole-number ratio, we divide the number of moles of each element by the smallest number of moles calculated:
- Ratio of tin to oxygen: 0.0177 mol / 0.0177 = 1 (tin), 0.0331 mol / 0.0177 = ~1.87 (oxygen)
Since we need whole numbers for the empirical formula, we multiply both numbers by a factor that turns 1.87 into a whole number. Multiplying both values by the smallest factor that yields a whole number for oxygen (roughly 2), we get:
- Whole number ratio: 1 * 2 = 2 (tin), 1.87 * 2 = ~3.74 which we round to 4 (oxygen)
Therefore, the empirical formula for the oxide of tin can be approximated as SnO2.