Write the balanced molecular and net ionic equation for the reaction that occurs when the contents of the two beakers are added together. (use the lowest possible coefficients. include states-of-matter under satp conditions in your answer.)

1) hydrochloric acid with nickel:

Balanced molecular equation: Ni(s) + 2HCl(aq) → NiCl₂(aq) + H₂(g).

Ionic equation: Ni(s) + 2H⁺(aq) + 2Cl⁻(aq) → Ni²⁺(aq) + 2Cl⁻(aq) + H₂(g).

Net ionic equation: Ni(s) + 2H⁺(aq) → Ni²⁺(aq) + H₂(g).

Nickel is oxidized from oxidation number 0 (Ni) to oxidation number +2, hydrogen is reduced from oxidation number +1 to oxidation number 0 (H₂).

2) sulfuric acid with iron:

Balanced molecular equation: Fe(s) + H₂SO₄(aq) → FeSO₄(aq) + H₂(g).

Ionic equation: Fe(s) + 2H⁺(aq) + SO₄²⁻(aq) → Fe²⁺(aq) + SO₄²⁻(aq) + H₂(g).

Net ionic equation: Fe(s) + 2H⁺(aq) → Fe²⁺(aq) + H₂.

Iron is oxidized from oxidation number 0 (Fe) to oxidation number +2, hydrogen is reduced from oxidation number +1 to oxidation number 0 (H₂).

3) hydrobromic acid with magnesium :

Balanced molecular equation: Mg(s) + 2HBr(aq) → MgBr₂(aq) + H₂(g).

Ionic equation: Mg(s) + 2H⁺(aq) + 2Br⁻(aq) → Mg²⁺(aq) + 2Br⁻(aq) + H₂(g).

Net ionic equation: Mg(s) + 2H⁺(aq) → Mg²⁺(aq) + H₂(g).

Magnesium is oxidized from oxidation number 0 (Mg) to oxidation number +2, hydrogen is reduced from oxidation number +1 to oxidation number 0 (H₂).

4) acetic acid with zinc:

Balanced molecular equation: Zn(s) + 2CH₃COOH(aq) → (CH₃COO)₂Zn(aq) + H₂(g).

Ionic equation: Zn(s) + 2H⁺(aq) + 2CH₃COO⁻(aq) → Zn²⁺(aq) + 2CH₃COO⁻(aq) + H₂(g).

Net ionic equation: Zn(s) + 2H⁺(aq) → Zn²⁺(aq) + H₂(g).

Zinc is oxidized from oxidation number 0 (Zn) to oxidation number +2 (Zn²⁺), hydrogen is reduced from oxidation number +1 to oxidation number 0 (H₂).

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements