- #1
jaumzaum
- 434
- 33
I was trying to solve the following exercise:
Choose the option that has the pair of substances whose chemical reaction is easily perceptiple
a)Br2(aq) + NaCl(aq)
b) Cl2(aq) + NaI(aq)
c) H2(g) + MgSO4(aq)
d) Ag(c) + ZnSO4(aq)
e) HCl(aq) + Cu(c)
I would say if the salt was an alkali salt, a would discolor the solution (Br2 is brown/red), as Br2 + H2O -> HBrO + HBr, and the equilibrum tends to form the products when the solution is basic. But the salt is NaCl, so nothing would happen
The second one I would say no change would be noticed
The third I would say some of the SO4-- could reduce to SO2 or some of the Mg++ to Mg, oxydating the H2 to H2O, but in a very low scale, so nothing would be noticed too
For the third, as ZnSO4 forms a acid solution, I would say some of the silver would oxydate to Ag+, even silver being a noble metal. This will occur with a low velocity but I would say it could be noticed.
For the last one, as Cu isn't a noble metal, I would say it will fastly oxidate to Cu2+, and the solution will color to blue, easily noticed
I chose e as the answer, but by book is saying it is b. Why is that?
Choose the option that has the pair of substances whose chemical reaction is easily perceptiple
a)Br2(aq) + NaCl(aq)
b) Cl2(aq) + NaI(aq)
c) H2(g) + MgSO4(aq)
d) Ag(c) + ZnSO4(aq)
e) HCl(aq) + Cu(c)
I would say if the salt was an alkali salt, a would discolor the solution (Br2 is brown/red), as Br2 + H2O -> HBrO + HBr, and the equilibrum tends to form the products when the solution is basic. But the salt is NaCl, so nothing would happen
The second one I would say no change would be noticed
The third I would say some of the SO4-- could reduce to SO2 or some of the Mg++ to Mg, oxydating the H2 to H2O, but in a very low scale, so nothing would be noticed too
For the third, as ZnSO4 forms a acid solution, I would say some of the silver would oxydate to Ag+, even silver being a noble metal. This will occur with a low velocity but I would say it could be noticed.
For the last one, as Cu isn't a noble metal, I would say it will fastly oxidate to Cu2+, and the solution will color to blue, easily noticed
I chose e as the answer, but by book is saying it is b. Why is that?