Chapter 3: Water

Label the following vocabular words in the example.

a

b

c

Solution

Solute

Solvent

What is a heat of evaporation?

• amount of heat required to raise the temperature of 1 gram of water by 1° Celsius

• amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1° Celsius

• amount of heat that must be absorbed for 1g of water to be converted into a gas

• as liquid evaporates, the remaining surface gets cooler

• a weak attraction between 2 polar covalent molecules

H3O+ is what ion?

A ph of 3 if how many more times acidic than a pH of 5?

• 10 times

• 100 times

• 1000 times

• 2 times

• None of the above

What feature of water allows for surface tension to exist? (Hint: think about why some organisms can walk on water).

• Cohesion

• Adhesion

• It's ability to moderate temperature changes

• It's ability to expand upon freezing

• How versatile it is as a solvent

Answer explanation

Water sticking so tightly to itself allows for surface tension.

Why do hydrogen bonds form?

Answer explanation

Hydrogen bonds form due to polarity of molecules.

For example, in water, the oxygen is highly electronegative so the electrons spend more time around oxygen than hydrogen. This gives oxygen a slight negative charge and hydrogen a slight positive charge.

What are some properties of water?

Answer explanation

Specific Heat

Universal Solvent

Moderates Temperature

Expansion Upon Freezing

What is a calorie?

• amount of heat required to raise the temperature of 1 gram of water by 1° Celsius

• amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1° Celsius

• amount of heat that must be absorbed for 1g of water to be converted into a gas

• as liquid evaporates, the remaining surface gets cooler

• a weak attraction between 2 polar covalent molecules

Select all examples of hydrophobic substances.

• Lipids

• Oil

• Glucose

• Proteins

• Wax

Answer explanation

Substances that do not dissolve in water are hydrophobic!

Find 1 covalent bond and circle it in yellow.

Find 1 hydrogen bond and highlight it in purple.

Answer explanation