The mass of magnesium cyanide needed to prepare the solution is 1.57 g
We'll begin by calculating the number of mole of Mg(CN)₂. This can be obtained as follow:
Volume = 275 mL = 275 / 1000 = 0.275 L
Molarity of Mg(CN)₂ = 0.075 M
Mole = Molarity x Volume
Mole of Mg(CN)₂ = 0.075 × 0.275
Mole of Mg(CN)₂ = 0.020625 mole
Mole of Mg(CN)₂ = 0.020625 mole
Molar mass of Mg(CN)₂ = 24 + 2(12 + 14) = 76 g/mol
Mass = mole × molar mass
Mass of Mg(CN)₂ = 0.020625 × 76
Mass of Mg(CN)₂ = 1.57 g
Therefore, 1.57 g of Mg(CN)₂ is needed to prepare the solution
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