If the procedure calls for 157mg of 4-tert-butylcyclohexanone, what mass of sodium borohydride should be added?

The equation for the reaction is shown below.

Molar mass of C₁₀H₁₈O (4-t-butylcyclohexanone) = (12.0×10 + 1.0×18 + 16.0) g/mol = 154.0 g/mol = 154.0 mg/mmol
Molar mass of NaBH₄ = (23.0 + 10.8 + 1.0×4) g/mol = 37.8 g/mol = 37.8 mg/mmol
(The molar masses used in lessons should be used instead.)

1 mole of C₁₀H₁₈O reacts with 1 mole of NaBH₄.
No. of moles of C₁₀H₁₈O reacted = (157 mg) / (154.0 mg/mmol) = 1.019 mmol
No. of moles of NaBH₄ should be added = 1.019 mmol
Mass of NaBH₄ should be added = (1.019 mmol) × (37.8 mg/mmol) = 38.5 mg