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3.50 Peroxyacyl mitrate (pan) is one of the components of smog. it is a compound of c, h n, and o. Determine the percent composition of oxygen and the empirical formula from the following percent composition by mass: 19.8 percent c, 2.50 percent h, 11.6 percent C. What is its molecular formula given that its molar mass is about 120 g? solve it accurately 4 decimal point always hydrogen is 1.008
Accepted Answer
1. Calculate the percentage of Oxygen:
Since the compound contains only C, H, N, and O, the percentage of oxygen can be calculated as:
%O = 100% - %C - %H - %N
%O = 100% - 19.8% - 2.50% - 11.6% = 66.1%
2. Determine the empirical formula:
Assume a 100g sample of PAN. This means we have 19.8g C, 2.50g H, 11.6g N, and 66.1g O.
Convert these masses to moles using the molar masses of each element:
Moles of C = 19.8g / 12.01 g/mol = 1.65 mol
Moles of H = 2.50g / 1.008 g/mol = 2.48 mol
Moles of N = 11.6g / 14.01 g/mol = 0.828 mol
Moles of O = 66.1g / 16.00 g/mol = 4.13 mol
Divide each mole value by the smallest mole value (0.828 mol) to obtain the mole ratio:
C: 1.65 mol / 0.828 mol ≈ 2
H: 2.48 mol / 0.828 mol ≈ 3
N: 0.828 mol / 0.828 mol ≈ 1
O: 4.13 mol / 0.828 mol ≈ 5
Therefore, the empirical formula of PAN is C₂H₃NO₅.
3. Determine the molecular formula:
Calculate the empirical formula mass:
Empirical formula mass = (2 x 12.01) + (3 x 1.008) + 14.01 + (5 x 16.00) ≈ 120 g/mol
Since the molar mass of PAN is approximately 120 g/mol, the molecular formula is the same as the empirical formula: C₂H₃NO₅.
Since the compound contains only C, H, N, and O, the percentage of oxygen can be calculated as:
%O = 100% - %C - %H - %N
%O = 100% - 19.8% - 2.50% - 11.6% = 66.1%
2. Determine the empirical formula:
Assume a 100g sample of PAN. This means we have 19.8g C, 2.50g H, 11.6g N, and 66.1g O.
Convert these masses to moles using the molar masses of each element:
Moles of C = 19.8g / 12.01 g/mol = 1.65 mol
Moles of H = 2.50g / 1.008 g/mol = 2.48 mol
Moles of N = 11.6g / 14.01 g/mol = 0.828 mol
Moles of O = 66.1g / 16.00 g/mol = 4.13 mol
Divide each mole value by the smallest mole value (0.828 mol) to obtain the mole ratio:
C: 1.65 mol / 0.828 mol ≈ 2
H: 2.48 mol / 0.828 mol ≈ 3
N: 0.828 mol / 0.828 mol ≈ 1
O: 4.13 mol / 0.828 mol ≈ 5
Therefore, the empirical formula of PAN is C₂H₃NO₅.
3. Determine the molecular formula:
Calculate the empirical formula mass:
Empirical formula mass = (2 x 12.01) + (3 x 1.008) + 14.01 + (5 x 16.00) ≈ 120 g/mol
Since the molar mass of PAN is approximately 120 g/mol, the molecular formula is the same as the empirical formula: C₂H₃NO₅.
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