Question

calculate the minimum amount of sodium borohydride (nabh4) in milligrams needed to fully reduce 0.35 mmol of benzil to hydrobenzoin, assuming that one mole of sodium borohydride can reduce four carbonyl groups. express your answer to the nearest milligram.

Answer 1

To fully reduce 0.35 mmol of benzil using NaBH4, 6.62 mg of NaBH4 is required, based on its molar mass of 37.83 g/mol and the fact that one mole can reduce four carbonyl groups.

Step-by-step explanation:

To calculate the minimum amount of sodium borohydride (NaBH4) needed to fully reduce 0.35 mmol of benzil to hydrobenzoin, we must consider that one mole of NaBH4 can reduce four carbonyl groups.

First, we determine the molar mass of NaBH4, which is approximately 37.83 g/mol. Since 0.35 mmol of benzil contains two carbonyl groups, we need to reduce 0.7 mmol of carbonyl groups in total.

Because one mole of NaBH4 can reduce four moles of carbonyl groups, we need 0.7 mmol / 4 = 0.175 mmol of NaBH4.

Next, we convert moles of NaBH4 to mass:

0.175 mmol × (37.83 g/mol) / 1000 = 0.00662 g or 6.62 mg (to the nearest milligram).

Therefore, the minimum amount of NaBH4 needed is 6.62 mg.