Question

Tin (Sn) exists in Earth's crust as SnO2. Calculate the percent composition by mass of Sn and O in SnO2.

Answer 1

Tin dioxide, SnO2, has a composition of approximately 78.80% tin and 21.20% oxygen by mass, calculated by the atomic weight of each element divided by the molar mass of the compound and multiplied by 100%.

Step-by-step explanation:

To calculate the percent composition by mass of an element in a compound, you must first determine the molar mass of the compound and then find the mass contribution by each element. The formula of tin dioxide is SnO2. The atomic weight of Sn (tin) is 118.7 g/mol, and the atomic weight of O (oxygen) is 16.00 g/mol. Therefore, the molar mass of SnO2 is 118.7 + (2 × 16.00) = 150.7 g/mol.

Next, you calculate the percent of tin in SnO2 by dividing the atomic weight of Sn by the molar mass of SnO2 and multiplying by 100%:
(118.7 g/mol ÷ 150.7 g/mol) × 100% ≈ 78.80%.

Then, calculate the percent of oxygen in SnO2 by adding the mass of the two oxygen atoms (2 × 16.00 g/mol = 32.00 g/mol) and dividing by the molar mass of SnO2, then multiply by 100%:
(32.00 g/mol ÷ 150.7 g/mol) × 100% ≈ 21.20%.

So, tin dioxide consists of approximately 78.80% tin and 21.20% oxygen by mass.

Answer 2

Sn = 78.77%

O = 21.23%

Step-by-step explanation:

The atomic mass of Sn = 118.71 g/mol

The atomic mass of O = 16 g/mol

The molar mass of SnO₂ = atomic mass of Sn + 2 X atomic mass of O

The molar mass of SnO₂= 150.71

Now, in each mole of SnO₂ there is one mole of Sn and two moles of O

The mass of Sn in 150.71 g of SnO₂ = 118.71

Percentage of Sn in 150.71 g of SnO₂ =
`(MassofSnX100)/(massofSnO_(2) )`

% of Sn =
`(118.71X100)/(150.71)=78.77`%.

Rest will be O = 100-78.77 = 21.23%