How many moles are in 2.7 mL of acetic anhydride, density of 1.082

molecular weight of Acetic Anhydride = 102 How many moles are in 2.7 mL of acetic anhydride, density of 1.082? Use the molecular weights that you have already calculated. Give two significant figures.

The Correct Answer and Explanation is:

To calculate the number of moles in 2.7 mL of acetic anhydride, we can break the calculation into two parts:

1. Convert the volume to mass using the density:
   The formula to find mass is: Mass=Density×Volume\text{Mass} = \text{Density} \times \text{Volume}Mass=Density×Volume We are given:
   • Density of acetic anhydride = 1.082 g/mL
   • Volume = 2.7 mL
   Mass=1.082 g/mL×2.7 mL=2.9214 g\text{Mass} = 1.082 \, \text{g/mL} \times 2.7 \, \text{mL} = 2.9214 \, \text{g}Mass=1.082g/mL×2.7mL=2.9214g
2. Convert mass to moles:
   To convert mass to moles, use the formula: Moles=MassMolar Mass\text{Moles} = \frac{\text{Mass}}{\text{Molar Mass}}Moles=Molar MassMass​ The molecular weight of acetic anhydride is given as 102 g/mol. Moles=2.9214 g102 g/mol=0.0286 mol\text{Moles} = \frac{2.9214 \, \text{g}}{102 \, \text{g/mol}} = 0.0286 \, \text{mol}Moles=102g/mol2.9214g​=0.0286mol When rounded to two significant figures, the number of moles is: Moles=0.029 mol\text{Moles} = 0.029 \, \text{mol}Moles=0.029mol

Conclusion: There are 0.029 moles of acetic anhydride in 2.7 mL, considering the density and molecular weight provided.