To determine the number of moles of glucose (C₆H₁₂O₆) in a 30g sample, we first need to calculate the molar mass of glucose using the given molar masses for carbon, hydrogen, and oxygen.
The molar mass of glucose (C₆H₁₂O₆) can be calculated as follows:
- Carbon: 6 atoms × 12.01 g/mol = 72.06 g/mol
- Hydrogen: 12 atoms × 1.01 g/mol = 12.12 g/mol
- Oxygen: 6 atoms × 16.00 g/mol = 96.00 g/mol
Now, summing these values gives us the total molar mass of glucose:
\[ \text{Molar mass of } C_6H_{12}O_6 = 72.06 , \text{g/mol} + 12.12 , \text{g/mol} + 96.00 , \text{g/mol} = 180.18 , \text{g/mol} \]
Next, we can calculate the number of moles using the formula:
\[ \text{Number of moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}} \]
Substituting in the values:
\[ \text{Number of moles} = \frac{30 , \text{g}}{180.18 , \text{g/mol}} \approx 0.1665 , \text{moles} \]
Rounding to two decimal places gives:
\[ 0.17 , \text{moles} \]
Therefore, the number of moles the chemist will use is: 0.17 moles.