The liquid contains 66.6c, 11.2% H and 22.2% 0. What is its molecular formula? How do i figure that?
Assume you have 100 grams of the stuff. then you have
66.6 g C, or xxxx moles
11.2 g H, or yyyyy moles
22.2 g O, or zzzzz moles
then examine xxxx, yyyy, zzzz. That is the mole ratio in the formula. Reduce it to a whole number ratio. Often, you can get it by dividing all three by the lowest.
To determine the molecular formula of the liquid, we need to calculate the empirical formula first. The empirical formula represents the simplest, whole-number ratio of atoms in a compound.
Given that the liquid contains 11.2% hydrogen (H) and 22.2% oxygen (O), we can find the ratio of these elements in the compound.
Step 1: Convert the percentages to grams.
Assuming you have 100 grams of the liquid:
- Hydrogen (H) = 11.2 grams
- Oxygen (O) = 22.2 grams
Step 2: Convert the grams to moles.
To convert grams to moles, you need to divide the mass of each element by its molar mass. The molar mass of hydrogen is approximately 1 g/mol, and the molar mass of oxygen is approximately 16 g/mol.
- Moles of hydrogen (H) = 11.2 g / 1 g/mol = 11.2 mol
- Moles of oxygen (O) = 22.2 g / 16 g/mol = 1.39 mol
Step 3: Find the mole ratio.
Divide the moles of each element by the smallest mole value obtained in Step 2 (the mole value of oxygen, in this case).
- Moles of hydrogen (H) = 11.2 mol / 1.39 mol = 8.06
- Moles of oxygen (O) = 1.39 mol / 1.39 mol = 1
Step 4: Determine the empirical formula.
The empirical formula is the whole-number ratio of atoms, so we need to convert the calculated mole ratios to whole numbers. Round them to the nearest whole number:
- Hydrogen (H) = 8
- Oxygen (O) = 1
Therefore, the empirical formula for the liquid is H8O.
Step 5: Determine the molecular formula.
To find the molecular formula, we need to know the molar mass of the compound. Unfortunately, this information is missing from the given question. The molecular formula will be a whole-number multiple of the empirical formula.
Suppose the molar mass of the compound is 72 g/mol. Divide the molar mass by the molar mass of the empirical formula (H8O) to find the multiple:
- Molecular mass of the compound = 72 g/mol
- Empirical formula mass (H8O) = 8 * 1 g/mol + 16 * 1 g/mol = 24 g/mol
- Multiple = Molecular mass of the compound / Empirical formula mass
= 72 g/mol / 24 g/mol
= 3
The molecular formula will be the empirical formula (H8O) multiplied by the multiple:
- Molecular formula = H8O * 3
= H24O3
The molecular formula of the liquid is H24O3. However, the molar mass of the compound is required to validate this answer.
To determine the molecular formula of a compound, we need to find the empirical formula first. The empirical formula represents the simplest whole-number ratio of atoms in a compound.
Given that the liquid contains 66.6% carbon (C), 11.2% hydrogen (H), and 22.2% oxygen (O), we will assume we have 100g of the compound to make the calculations easier.
To calculate the number of moles of each element in the compound, we can use their respective molar masses:
- Carbon (C): Atomic mass of C = 12.01 g/mol
Moles of C = Mass of C / Molar mass of C
= (66.6 g / 100 g) / 12.01 g/mol
= 0.555 mol
- Hydrogen (H): Atomic mass of H = 1.01 g/mol
Moles of H = Mass of H / Molar mass of H
= (11.2 g / 100 g) / 1.01 g/mol
= 0.111 mol
- Oxygen (O): Atomic mass of O = 16.00 g/mol
Moles of O = Mass of O / Molar mass of O
= (22.2 g / 100 g) / 16.00 g/mol
= 0.139 mol
Next, we need to find the simplest whole-number ratio of moles. We can divide each value by the smallest number of moles (in this case, 0.111 mol) to normalize the ratio:
- Carbon: 0.555 mol / 0.111 mol = 5
- Hydrogen: 0.111 mol / 0.111 mol = 1
- Oxygen: 0.139 mol / 0.111 mol = 1.25 (approx.)
Now, we multiply these whole numbers by the subscripts in the empirical formula:
C5H1.25O1.25 (approx.)
Since we cannot have fractions in a molecular formula, we need to multiply each subscript by 4 to ensure whole numbers:
C5H5O5
Therefore, the molecular formula of the compound is C5H5O5.