Mod. 2 Water

Question 1

What are the properties of water?

Answer 1

• thermally stable
• polar molecule (can be a solvent)
• insulator
• surface tension
• transparent

Question 2

What makes water thermally stable?

Answer 2

has a low freezing point and a high boiling point meaning it is liquid in a wide range of temperatures (0-100)

Question 3

Why is is useful that water is a polar molecule?

Answer 3

because of the positive and negative zones, water attracts charged particles, dissolving them. Water acts as a solvent.

Question 4

What makes water a good insulator?

Answer 4

water expands when when it freezes, making it less dense so it floats on top of liquid water. this meas the water underneath remains liquid rather than becoming colder.

Question 5

Why does water have surface tension?

Answer 5

because of its cohesive properties. Water molecules are attracted to each other in a liquid state because of the polar nature of the bonds formed between O and 2H. the electronegative oxygen is attracted to the electropositive Hs.

Question 6

Why is the transparency of water important?

Answer 6

Water is transparent, meaning light can travel through it, so there can be life under water. The eye developed under water, allowing animals live under water, and plants can photosynthesise underwater.

Question 7

Cohesion

Answer 7

water molecules are polar so have delta positive and delta negative zones that are attracted to the opposite charge on other molecules. This causes the water to form droplets and the molecules to stay together as a body. And this keeps the boiling point high.

Question 8

Adhesion

Answer 8

Because of the polar nature of the water molecules, the delta charges are sometimes attracted to molecules with a greater charge, such as ionic molecules.