Chemistry problem

Question

A student makes a solution that is 4.5 m. If she used 100 kg of water, how many moles of solute did she use?

Answer 1

The definition of a molal (m) solution is moles per kg of solvent.

Here we have 100 kg of solvent, and a m of 4.5. So, we can easily solve for the number of moles.

m = moles/kg

4.5 = x moles/100 kg

x moles = 450 moles