A mass of 0.630 g of NaCl is dissolved in 525 g of water.
CAlculate the molality.
mass of NaCl= 0.630g
mass of H20= 525g
molar mass of NaCl= 58.44
This is what i did it keeps telling me the answer is wrong.
Convert grams to moles of NaCl
0.630 * 1 mol NaCl/58.44= 0.01078
Molality= moles of solute/ mass of
solvent (kg)
0.01078/ 0.0525 = 0.2053m NaCl
Can some one please double check where im going wrong
525 g solvent is 0.525 kg, not 0.0525 kg.
when u convert 525g to kg, it should be .525kg
2.05x10^-2 m
Your initial steps in converting grams to moles of NaCl are correct. Here's a breakdown of the calculation and the correction:
1. Convert grams of NaCl to moles:
0.630 g NaCl * (1 mol NaCl / 58.44 g NaCl) = 0.01078 mol NaCl
However, there is a mistake in the next step:
2. Calculate molality:
Molality = moles of solute / mass of solvent (kg)
Molality = 0.01078 mol NaCl / 0.525 kg H2O = 0.02055 m NaCl
The correct molality is 0.02055 m NaCl, not 0.2053 m NaCl.
So, your mistake is purely in the calculation of the molality - you just misplaced the decimal point. Make sure to recheck your mathematical operations for accuracy.