The mass of potassium hydroxide required to make 300.ocm^{3} of 0.4 moldm^{-3} solution is {KOH = 56.0}

Answer Details

To calculate the mass of potassium hydroxide required, we can use the formula: mass = moles × molar mass First, let's calculate the number of moles of potassium hydroxide required to make 300 cm^{3} of 0.4 mol dm^{-3} solution: moles = concentration × volume moles = 0.4 mol dm^{-3} × 0.3 dm^{3} = 0.12 moles The molar mass of potassium hydroxide (KOH) is 56.0 g mol^{-1}, so we can now calculate the mass of KOH required: mass = moles × molar mass mass = 0.12 moles × 56.0 g mol^{-1} = 6.72 g Therefore, the mass of potassium hydroxide required to make 300 cm^{3} of 0.4 mol dm^{-3} solution is 6.72 g. So, the correct option is (C) 6.72g.