Chemistry Chapter 3: Reactions and Stoichiometry

Question 1

1 cubic meter is equal to _______ cubic centimetres

Answer 1

(100cm)^3 which is 10^6 cubic centimetres

Question 2

Which compounds appear colored in solution?

Answer 2

Compounds with transition metal ions (in both solid and aqueous forms) because transition metals have unfilled d-orbitals

This allows for the metal-to-ligand or d-d orbital transfer of electrons through absorption of photons in the visible light region of the electromagnetic spectrum that we see as color.

Question 3

Whenever a carbonate (CO₃²⁻) reacts with an acid (H⁺), it will always produce:

Answer 3

Water (H₂O)
Carbon dioxide (CO₂)
A salt (in this case, CaCl₂)
This pattern applies broadly to most carbonate + acid reactions, so you can remember this as a general rule.

Question 4

Hydration/solvation

Answer 4

occurs when the attractive force of an ion molecule causes a thin shell of water molecules to surround it.

Question 5

metathesis reaction

Answer 5

is synonymous with a double displacement reaction

Question 6

Avogardo’s number

Answer 6

6 x 10^23 particles per mol

Question 7

Hydrolysis

Answer 7

is a chemical reaction in which a molecule is broken down into smaller parts by the addition of water.

Question 8

What happens when you react acid and carbonate ion?

Answer 8

You get CO2 and water and salt

Question 9

True or false:
The limiting reagent is always the reactant present in the smallest molar quantity.

Answer 9

FALSE, it’s the reactant that runs out first

Question 10

Grignard Reaction

Answer 10

A Grignard reagent (R-MgX) reacts with electrophiles like carbonyl compounds (aldehydes, ketones, esters, CO₂) to form alcohols or carboxylic acids.
The reaction is widely used to synthesize alcohols and extend carbon chains in organic chemistry.

Does NOT react with an alkane

Question 11

How to make soap

Answer 11

made by saponification, where triglycerides (fats) react with strong bases (NaOH or KOH) to form fatty acid salts (soap) and glycerol.

Question 12

Why are soaps basic?

Answer 12

✅ Made from a weak acid (fatty acid) + strong base (NaOH/KOH).
✅ The carboxylate ion (-COO⁻) does not donate H⁺, but instead, can accept it.
✅ In water, carboxylate (-COO⁻) undergoes slight hydrolysis, producing OH⁻:

✅ This increases pH > 7, making soap basic despite being called a “fatty acid soap.”