Question

A tank holds 10000 Kg of NaHCO3 solution at 60 degree C. Amount of NaHCO3 in the initial solution is 100 Kg. Temperature of the solution is reduced to 40 degree C. You MUST CRYSTALIZE OUT 50 KG OF NaHCO3.How much water is being evaporated? @aaronq

Answer 1

Can you please explain how do I go about this?

Answer 2

this question is really weirdly worded. But lets try it,

you initially have \(\sf \dfrac{100~kg}{10000~kg}=1\% \) solution (i.e. not saturated)

in fact, 10000-100= 9900 kg are water

40 celsius is 104 F, which has a max solubility of 11.3 %

because we have 100 kg and we need to crystalize half,

we need to make 50 kg equal to 11.3% of the solution

the amount of water that should be left should equal to \(m_{water}\):

\(\dfrac{50~kg}{50~kg+m_{water}}=11.3\%\)

\(m_{water}=392.477~kg\)

Now just find how much water needs to evaporate