Question

Calculate the moles of sucrose, C12H22O11, in a 15.0-g sample of this substance.1. 0.0438 moles2. 1.42 moles3. 2.57 moles4. 0.00168 moles5. 6.10 moles

Answer 1

To find the moles of sucrose in a 15-g sample, divide the mass by the molar mass of sucrose (342.34 g/mol), which results in 0.0438 moles. This calculation matches the first option and our estimation.

Step-by-step explanation:

To calculate the moles of sucrose in a 15-g sample, one must first know the molecular weight of sucrose, which is the sum of the atomic masses of all atoms in a molecule of sucrose (C12H22O11). Given that the molar mass of sucrose is 342.297 g/mol:

• C (carbon): 12.01 g/mol x 12 = 144.12 g/mol
• H (hydrogen): 1.01 g/mol x 22 = 22.22 g/mol
• O (oxygen): 16.00 g/mol x 11 = 176.00 g/mol

Add these values together to get the molar mass: 342.34 g/mol. To find the moles, divide the mass of the sample by the molar mass:

Number of moles of sucrose = mass in grams / molar mass

Number of moles of sucrose = 15.0 g / 342.34 g/mol = 0.0438 moles

This means that 0.0438 moles of sucrose are contained in a 15-g sample of sucrose, which is consistent with our rough estimate and aligns with the first option provided.

Answer 2

`0.0438\text{ mole}`

Step-by-step explanation:

Here, we want to calculate the number of moles of sucrose in the mass of the sample

Mathematically, we have that as:

`\begin{gathered} Number\text{ of moles = }\frac{mass}{molar\text{ mass}} \\ \end{gathered}`

The mass given is 15g, and the molar mass is 342.3 g/mol

Thus, we have the number of moles as:

`Number\text{ of moles = }(15)/(342.3)\text{ = 0.0438 mole}`