Help with AP Chem questions?

Question

1. Hydrogen can have oxidation states of +1, 0, and -1. Write the formula and names of for one chemical species for each of these oxidation states.

2. Name the ion: HSeO3 -

3. Write the formula for each of the following substances.

(a) zinc carbonate can be heated to form zinc oxide and carbon dioxide

(b) on treatment with hydrofluoric acid, silicon dioxide forms silicon tetrafluoride and water

(c) sulfur dioxide reacts with water to form sulfurous acid

(d) the substance hydrogen phosphide aka phosphine, is a toxic gas

(e) perchloric reacts with cadmium to form cadmium perchlorate

(f) vanadium(III) bromide is a colored solid

Answer 1

NH3 ammonia for +1

H2 gas for 0

LiH for -1  Lithium hydride

If HSO3 is bisulfite, this should be biselenite ion

These are not balanced.  For 2 points you want balanced??

ZnCO3 -> ZnO + CO2

SiO2 + HF -> SiF4 + H2O

SO2+H2O -> H2SO3

PH3

Cd + HClO4 -> Cd(ClO4)2

VBr3.  

Answer 2

1) water, H2O for +1 oxidation state, Sodium hydride, NaH for -1 oxidation state, hydrogen gas, H2 for 0 oxidation state.

2) Hydrogen selenite or biselenite

3)

a) ZnCO3===>ZnO + CO2

b) SO2 + HF===>SiF4 + H2O

c) SO2 + H2O===>H2SO3

d) PH3=Phosphine

e) HClO4 + Cd===>Cd(ClO4)2 + H2

f) VBr3=Vanadium(III) Bromide

Note that I didn't balance the equations or provide the states of matter because you didn't ask.