Question

The following method is used to make crystals of hydrated nickel sulfate. An excess of nickel carbonate, 12 g, was added to 40 cm cubic of sulfuric acid 2 mol/dm cubic. The unreacted nickel carbonate was filtered off and the filtrate evaporated to obtain the crystals. (Mass of 1 mol of NiSO4.7H2O= 281 g) (Mass of 1 mol NiCO3= 119 g)

-Calculate the mass of unreacted nickel carbonate by these steps. (Number of moles of H2SO4 in 40 cm cubic of 2 mol/dm3 acid= 0.08)
--Number of moles of NiCO3 reacted= ......
--Mass of nickel carbonate reacted=.........
--Mass of unreacted nickel carbonate=.....

Answer 1

ill write you steps sou you learn something ... i hope, but if you cant solve it ill write you all equations: first you write an reaction equation and balance it, after that calculate how many moles of NiCO3 you realy have by dividing 12g with 119gmol-1. then you see which relationship do NiCO3 and H2SO4 have (1:1) so amount of reacted NiCO3 is equal to amount of reacted H2SO4 (n(NiCO3)=n(H2SO4) and now you know that amount of NiCO3 that reacted is the same as of H2SO4, now its simple you just multiply that amount with molar mass and get mass of NiCO3 that reacted, and by subtracting the moles from (1:1) relationship and ones you calculated from 12 g you get amount of moles that didn't react and multiplying it with molar mass you get mass of unreacted NiCO3.

Answer 2

thanks alot! I'll try to do it. I know how to write the equations and balance em. Hope that helps me to solve this question :)