Bio-1406: Chapter 3

What is specific heat?

Heat needed to change 1g substance by 1°C.

Why does water resist temperature change?

Hydrogen bonds absorb the heat.

What is evaporative cooling?

Evaporation cools the remaining liquid.

What is a solute?

The substance dissolved.

What is solvent?

The dissolving substance.

What is an aqueous solution?

Water is the solvent.

What is hydrophilic?

Attracted to water/ dissolves.

What is hydrophobic?

Repelled by water/ does not mix.

What does pH measure?

Acidity, or base.

What does pH measure by?

Hydrogen ions (H⁺).

What does acid donate?

H⁺ ions.

What does base donate?

Hydroxide ion (OH^-).

Why is water polar?

Oxygen pulls electrons closer.

What charge/s does water have?

Oxygen δ⁻, Hydrogen δ⁺

What holds water molecules together?

Hydrogen bonds.

Why does water dissolve well?

Ionic and polar substances.

What is a calorie?

Heat needed to raise 1g of water up 1 degree C.

What is a kilocalorie?

1,000 calories.

What is water’s specific heat?

1 cal/ g°C

Why does ice float?

Ice is less dense than liquid water.

Why is ice less dense?

Hydrogen bonds form an open lattice.

How much less dense is ice?

About 10%.

When is water most dense?

4° C

What does high H⁺ mean?

Low pH: acidic.

What does low H⁺ mean?

High pH: base.

What does -log[H⁺] mean?

More H⁺ = lower pH.

What is the tool used to test pH?

Litmus paper.

Normal human cellular pH range?

7.2-7.6.

Main body buffer system?

Carbonic acid-bicarbonate.

How is carbonic acid removed?

Turn to CO₂, and exhaled.

Dissolved CO₂ makes…?

Carbonic acid.

What happens when a ionic compound dissolves in water?

Each ion surrounded by water molecules called a hydrogen shell