easy as pie.. apparently!

[ellis182]

Hey guys im struggling with these two questions! my textbook is so [poor quality] its from 1982 and [very] useless! can anyone point me in the right direction here?


1) Determine "x" in the following half equation.

x + 14H+ + 6e- 2Cr3+ + 7H2O


2) Chlorine gas can be prepared in the laboratory by the reaction of
manganese dioxide with hydrochloric acid:

MnO2(s) + 4HCl(aq) MnCl2(aq) + 2H2O(l) + Cl2(g)

How much MnO2 should be added to excess HCl to obtain 275 mL of
chlorine gas at 5.0oC and 86.6 kPa?

Any help would be greatly appreciated!

*I moderated your language. Please remember kids have access to this forum. - Rob