S2 Chemistry - Balancing Equations + Acids/Alkali + Equations

Choose one equation that follows this: acid + metal -> salt + hydrogen

• hydrochloric acid + sodium -> sodium chloride + hydrogen gas

• ethanoic acid + magnesium -> magnesium ethanoate + hydrogen atom

• sulfuric acid + lithium -> lithium sulfate + hydrogen ion

• phosphoric acid + potassium -> potassium phosphate + hydrogen gas

Answer explanation

They all follow the format given in the question.

The hydrogen here refers to hydrogen gas

This equation is balanced: H₂SO₄ + CaCO₃ -> CaSO₄ + CO₂ + H₂O

• True

• False

Answer explanation

All are balanced.

Which exists as a chemical compound.

• KO

• H²

• H₂

• Al₂(SO₄)₃

Answer explanation

KO -> K₂O
H² ? It's not H squared.
H₂ is not a compound.

The remaining option is a compound because charges are balanced.

acid + ammonium salt -> salt + ammonia gas + water

• True

• False

Answer explanation

It's alkali not acid + ammonium salt -> salt + ammonia gas + water

MgCl + AgNO₃ -> MgNO₃ + AgCl

Correct or wrong?

• Correct

• Wrong

Answer explanation

MgCl? This is already wrong so there is no point checking to balance the charges already!

Name of these chemicals:

H₂SO₄ , H₃PO₄ , CH₃CO₂H , HNO₃

• hydrogen sulfate, hydrogen phosphate, hydrogen ethanoate, hydrogen nitrate

• hydrogen sulfate, hydrogen phosphate, ethanoate hydrogen, hydrogen nitrate

• sulfuric acid, phosphoric acid, ethanoic acid, nitric acid

• hydrogen sulfide, hydrogen phosphide, hydrogen ethanoate, hydrogen nitride

Answer explanation

They are all acids man.

Can Fe₂O₃ be formed?

• Yes

• No

Answer explanation

This is iron(III) oxide. Remember iron has different ions with different charges (Fe²⁺, Fe³⁺)

Balance the equation.

CH₄ + O₂ -> CO₂ + H₂O

• CH₄ + 2O₂ -> CO₂ + 2H₂O

• CH₄ + O₂ -> CO₂ + H₂O (already balanced)

• CH₄ + 2O₂ -> CO₂ + H₂O

• 2CH₄ + O₂ -> CO₂ + 2H₂O

This equation is NOT balanced.

Fe + S -> FeS

• True
• False

Answer explanation

With a quick glance, you should be able to tell that there is 1 iron(II) ion on both sides on 1 sulfide ion on both sides.

Do you know your cations, anions, acids and the 5 important equations?

• Yes

• Yes

• Yes

• No

Answer explanation

... nice one