Answer:
The mass of 0.40 moles NaBH4 is 15.14 grams
Explanation:
Step 1: Data given
sodium borohydride = NaBH4
Number of moles sodium borohydride = 0.40 moles
Atomic mass of Na = 22.99 g/mol
Atomic mass of B = 10.81 g/mol
Atomic mass of H = 1.01 g/mol
Step 2: Calculate the molar mass of NaBH4
Molar mass = 22.99 g/mol + 10.81 g/mol + 4*1.01 g/mol
Molar mass NaBH4 = 37.84 g/mol
Step 3: Calculate mass of NaBH4
Mass NaBH4 = moles NaBH4 * molar mass NaBH4
Mass NaBH4 = 0.40 moles NaBH4 * 37.84 g/mol
Mass NaBH4 = 15.136 grams ≈ 15.14 grams of NaBH4
The mass of 0.40 moles NaBH4 is 15.14 grams