the question says: Calculate the mass of soap (NaC17H35COO) which contains 1.25 grams of Carbon. Do I use the percentage composition of soap and the mole?
1.25 g C/12 = mols C
Convert to mols soap.
grams soap = mols soap x molar mass soap.
To calculate the mass of soap that contains 1.25 grams of carbon, you can indeed utilize the percentage composition of the soap and the concept of moles.
Here's how you can approach the problem step by step:
1. Determine the molar mass of the compound: In this case, the compound is sodium stearate (NaC17H35COO). To calculate the molar mass, you need to sum the atomic masses of all the elements in the compound. The atomic mass of sodium (Na) is 22.99 g/mol, carbon (C) is 12.01 g/mol, hydrogen (H) is 1.01 g/mol, and oxygen (O) is 16.00 g/mol. Therefore, the molar mass of sodium stearate is:
(1 × Na) + (17 × C) + (35 × H) + (2 × O)
= 22.99 g/mol + 17 × 12.01 g/mol + 35 × 1.01 g/mol + 2 × 16.00 g/mol
2. Calculate the percentage composition of carbon in the compound: The percentage composition is the proportion of the molar mass contributed by carbon. We can calculate the percentage composition of carbon by dividing the molar mass of carbon (12.01 g/mol) by the molar mass of sodium stearate, and then multiplying by 100:
[12.01 g/mol ÷ (22.99 g/mol + 17 × 12.01 g/mol + 35 × 1.01 g/mol + 2 × 16.00 g/mol)] × 100
3. Use the percentage composition to find the mass of soap: The next step is to use the percentage composition to determine how much soap is required to contain 1.25 grams of carbon. To do this, you can set up a proportion using the known mass of carbon (1.25 grams) and the percentage composition of carbon:
(1.25 g) ÷ [12.01 g/mol ÷ (22.99 g/mol + 17 × 12.01 g/mol + 35 × 1.01 g/mol + 2 × 16.00 g/mol)] × 100
4. Solve the proportion and calculate the mass of soap: Simply solve the proportion you set up in the previous step.
Using these steps, you will be able to calculate the mass of soap (NaC17H35COO) that contains 1.25 grams of carbon.