a compound contains only carbon hydrogen and oxygen analysis of a sample showed that it contained by mass 53.4% carbon and 11.1% hydrogen . what is the simplest formula for this compound .. step by step plese
%O = 100 - %C - %H
Take a 100 g sample which gives
53.4g C
11.1g H
35.5g O
mols C = 53.4/12 = ?
mols H = 11.1/1 = ?
mols O = 35.5/16 = ?
Now find the ratio of the atoms to each other (as whole numbers) with the smallest number being 1.00. The easy way to do that is to divide the smallest number above by itself, then divide the other numbers by the same small number. Round to whole numbers.
C2h4o
To find the simplest formula for a compound, you need to determine the ratio of the elements present. Here are the steps:
1. Start by assuming we have 100 grams of the compound. This assumption makes it easier to calculate percentages.
2. Calculate the mass of carbon in the compound: 53.4% of 100g = 53.4g.
3. Calculate the mass of hydrogen in the compound: 11.1% of 100g = 11.1g.
4. Calculate the mass of oxygen in the compound: Since the compound contains only carbon, hydrogen, and oxygen, the remaining mass is due to oxygen: 100g - (53.4g + 11.1g) = 35.5g.
5. Convert the masses to moles by dividing by the atomic masses:
- Carbon: 53.4g / 12.01 g/mol (atomic mass of carbon) = 4.45 moles of carbon.
- Hydrogen: 11.1g / 1.01 g/mol (atomic mass of hydrogen) = 10.99 moles of hydrogen.
- Oxygen: 35.5g / 16.00 g/mol (atomic mass of oxygen) = 2.22 moles of oxygen.
6. Divide each number of moles by the smallest number of moles to obtain the simplest ratio:
- Carbon: 4.45 moles / 2.22 moles = 2.
- Hydrogen: 10.99 moles / 2.22 moles = 4.96 (round to the nearest whole number, which is 5).
- Oxygen: 2.22 moles / 2.22 moles = 1.
7. The simplest formula is written using these ratios as subscripts, so the formula for the compound is C2H5O.
To find the simplest formula for a compound based on the given mass percentages, we need to follow these steps:
Step 1: Assume you have a 100g sample of the compound.
Step 2: Convert the mass percentages of carbon and hydrogen into grams.
53.4% carbon = 53.4g carbon
11.1% hydrogen = 11.1g hydrogen
Step 3: Determine the mass of oxygen in the sample by subtracting the mass of carbon and hydrogen from the total sample mass.
Total mass of the sample = 100g
Mass of carbon = 53.4g
Mass of hydrogen = 11.1g
Mass of oxygen = Total mass - Mass of carbon - Mass of hydrogen
= 100g - 53.4g - 11.1g
= 35.5g
Step 4: Convert the masses of carbon, hydrogen, and oxygen to moles using their respective atomic masses.
Atomic mass of carbon (C) = 12.01 g/mol
Atomic mass of hydrogen (H) = 1.01 g/mol
Atomic mass of oxygen (O) = 16.00 g/mol
Moles of carbon = Mass of carbon / Atomic mass of carbon
= 53.4g / 12.01 g/mol
≈ 4.446 mol
Moles of hydrogen = Mass of hydrogen / Atomic mass of hydrogen
= 11.1g / 1.01 g/mol
≈ 10.99 mol
Moles of oxygen = Mass of oxygen / Atomic mass of oxygen
= 35.5g / 16.00 g/mol
≈ 2.219 mol
Step 5: Divide each of the moles obtained in step 4 by the smallest number of moles to get the simplest ratio.
Simplest ratio = Moles of carbon : Moles of hydrogen : Moles of oxygen
≈ 4.446 mol : 10.99 mol : 2.219 mol
Divide all the values by 2.219 (the smallest number of moles):
≈ 4.446 mol / 2.219 mol : 10.99 mol / 2.219 mol : 2.219 mol / 2.219 mol
≈ 2 : 4.96 : 1
Step 6: Round off the ratios to the nearest whole numbers to obtain the subscripts in the empirical formula.
The empirical formula of the compound is CH2O.
Therefore, the simplest formula for this compound is CH2O.