Answer: Amount of [tex]NaBH_4[/tex] required will be 66.2025 g
Explanation:
We are given:
1 equivalent of [tex]NaBH_4[/tex] can reduce 4 equivalents of carbonyl functional groups.
Benzil has 2 carbonyl functional groups. Thus, 1 equivalent of [tex]NaBH_4[/tex] will reduce 2 equivalents of benzil.
Moles of Benzil given = 0.35 mmol = [tex]3.5\times 10^{-4}mol[/tex] (Conversion factor: 1 mol = 1000 mmol)
By Stoichiometry:
2 moles of benzil reacts with 1 mole of [tex]NaBH_4[/tex]
So, [tex]3.5\times 10^{-4}mol[/tex] of benzil will react with = [tex]\frac{1}{2}\times 3.5\times 10^{-4}=1.75\times 10^{-4}mol[/tex] of [tex]NaBH_4[/tex]
To calculate the mass of [tex]NaBH_4[/tex], we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Moles of [tex]NaBH_4=1.75\times 10^{-4}mol[/tex]
Molar mass of [tex]NaBH_4[/tex] = 37.83 g/mol
Putting values in above equation, we get:
[tex]1.75\times 10^{-4}mol=\frac{\text{Mass of }NaBH_4}{37.83g/mol}\\\\\text{Mass of }NaBH_4=66.2025g[/tex]
Hence, amount of [tex]NaBH_4[/tex] required will be 66.2025 g