Aslamualaikum guys need help

[Abdullahbutt]

In the last part where u have to calc. The percentage they used the conc. Of mg2+ we found out in the part above divided by the total (0.05) in sea water and took its percentage they considred it to be of the mg 2+ which was left behind,then substracted it from 100 to find the one which was extracted.Shouldnt the one without substracting it from 100 be of extracted coz mgoh2 is precipitated?

 

[Abdullahbutt]

In the last part where u have to calc. The percentage they used the conc. Of mg2+ we found out in the part above divided by the total (0.05) in sea water and took its percentage they considred it to be of the mg 2+ which was left behind,then substracted it from 100 to find the one which was extracted.Shouldnt the one without substracting it from 100 be of extracted coz mgoh2 is precipitated?

Talking about biii(in about mid of the page)