Question

A factory has acidic wastewater to be neutralized. Analysis shows that the wastewater has a hydrogen ion concentration of 0.60 moldm-3. Calculate the mass of slaked lime, Ca(OH)2, that should be added to each dm3 of the wastewater to completely neutralize the acid.

Answer 1

@Callisto

Answer 2

Can you write the ionic equation?

Answer 3

ahh..... is it : H+ + OH- →H2O?
O.o i don't know what have I learnt in Chemistry lesson....my teacher always absent

Answer 4

It should be
\[2H^{+} + Ca(OH)_2\rightarrow Ca^{2+} + H_2O\]

Answer 5

ahhhh.....................
and?

Answer 6

From the equation, two moles of H+ ions require one mole of Ca(OH)2 for complete neutralization. Now, for each dm^{-3}, you have 0.60 mole of H+, how many moles of Ca(OH)2 do you need for complete neutralization?

Answer 7

1.2mol?

Answer 8

No..

Answer 9

oops..

Answer 10

0.3 /.\??

Answer 11

Yes.

Answer 12

Mole = mass / molar mass
So,
mass required = no. of moles of Ca(OH)2 x molar mass of Ca(OH)2

Answer 13

ah ha, let me work it out

Answer 14

22.23g?

Answer 15

Yes.

Answer 16

ah ha, thanks:)

Answer 17

Welcome :)