Water

Question 1

% of H2O in the human body?

Answer 1

60

Question 2

% of 💦in the human cell?

Answer 2

80

Question 3

Describe the structure of 💦.

Answer 3

H+ and O2- are held together by “polar covalent bonds” involving an unequal sharing of Electrons.

Question 4

What causes electrical attraction between 💦?

Answer 4

Weak Hydrogen bonds.

The positively polarized H+ is attracted to the negatively polarized O2-

Question 5

Why is water important?

Name five facts about water.

Answer 5

1. It has a very high surface tension.
2. Solid water [ice] is less dense [lighter] than liquid water. As water freezes it rises.
3. Water has a high heat capacity. Therefore, it resist temperature changes.
4. Water is a universal solvent.

Due to water’s polarization, it’s able to have these properties.

Question 6

What is a polar covalent bond?

Answer 6

It’s an unequal sharing of electrons.

Question 7

What is an example of a polar covalent bond?

Answer 7

Water

O2- is bigger therefore ‘hogs’ the [e-] more than H+.

Therefore, the hydrogen is positively polarized and the Oxygen is more negatively polarized.

Question 8

When water spills, the molecule tends to ‘bead up’.

Why?

Answer 8

They are joined together by weak hydrogen bonds.

This is due to the negatively polarized O2- being attracted to the 2H+.

Question 9

Why is it important that our body is made up mostly of water?

Answer 9

Water is resistant to temperature change.

Hence, it helps maintain our body temperature.

Question 10

How would a water molecule break apart?

Answer 10

By releasing a H+ and OH-.