How much KOH is needed to make 2 molality solution if water used was 2

1.	How much KOH is needed to make 2 molality solution if water used was 200 gm.
Answer» Answer: 22.4g Explanation: molality = MOLES of solute / kilograms of solvent ATQ, molality = 2 amount of solvent = 200GM = 0.2kg ∴ 2 = no. of moles of KOH/ 0.2 => no. of moles of KOH = 2 X 0.2 = 0.4 mol we know that amount of substance(in gm) = no. of moles x molar mass of substance molar mass of KOH= 39+16+1 = 56 amu ∴, amount of KOH= 0.4 x 56 = 22.4g

How much KOH is needed to make 2 molality solution if water used was 200 gm.

Answer»

Answer: 22.4g

Explanation:

molality = MOLES of solute / kilograms of solvent

ATQ,

molality = 2

amount of solvent = 200GM = 0.2kg

∴ 2 = no. of moles of KOH/ 0.2

=> no. of moles of KOH = 2 X 0.2 = 0.4 mol

we know that amount of substance(in gm) = no. of moles x molar mass of substance

molar mass of KOH= 39+16+1 = 56 amu

∴, amount of KOH= 0.4 x 56 = 22.4g