1.) Tin foil will oxidize when exposed to oxygen forming tin (II) oxide.
2.) When solid potassium is added to water, hydrogen gas and aqueous potassium hydroxide are produced.
3.) Solid calcium hydrogen carbonate reacts with hydrochloric acid to produce aqueous calcium chloride, water, and carbon dioxide gas.
4.) Mercury (II) Bromide decomposes into its elements when treated with electricity.

I would really appreciate some help, for my chemistry honors teacher did not teach us how to do this, but yet he put this on the final exam.:confused:
Thank you.:D

1.) Tin foil will oxidize when exposed to oxygen forming tin (II) oxide.


Tin foil is... drumroll... tin! (actually, a lot of "tin" foil is aluminum foil).
tin: Sn
Oxygen: O2
Tin(II) Oxide: SnO

Sn + O_2 \rightarrow SnO



2.) When solid potassium is added to water, hydrogen gas and aqueous potassium hydroxide are produced.


Solid potassium: K
Water: H2O
Hydrogen gas: H2
Potassium Hydroxide: KOH

2K + 2H_2O \rightarrow H_2 + 2KOH



3.) Solid calcium hydrogen carbonate reacts with hydrochloric acid to produce aqueous calcium chloride, water, and carbon dioxide gas.


Calcium Hydrogen Carbonate: Ca(HCO3)2
Hydrochloric acid: HCl
Calcium Chloride: CaCl2
Water: H2O
Carbon dioxide: CO2

Ca(HCO_3)_2 + HCl \rightarrow CaCl_2 + H_2O + CO_2

I'll let you balance the equation.



4.) Mercury (II) Bromide decomposes into its elements when treated with electricity.


Mercury(II) Bromide: HgBr2
"Its elements:" Hg (mercury), Br2 (bromine)

HgBr_2 \rightarrow Hg + Br_2

If you're in an honors chemistry class, I think these are fairly simple problems.