Water

Question 1

Draw hydrogen bonding

Answer 1

H+
    -
O-
    -
        H+

Question 2

How does the density of the water decreasing to temperatures before 4c, so ice floats on top, help organisms survive in ponds?

Answer 2

Density of the water decreases when it turns to ice as the particles are arranged further apart in a lattice shape, allowing the ice to float on top and it acts as insulating layer. Allowing it t keep a regular temperature. and organisms can carry on moving

Question 3

How does water acting as a solvent for ions (nitrates) help organisms survive?

Answer 3

By water being a solvent it allows for substances to be dissolved in it as the positive water molecules attract to the negtive ions and vise versa , allowing the water to completely surround it; making a solvent. Therefore,this allows for the plants and animals to uptake the nutrients in the water- need nitrates for amino acids

Question 4

How does water being able to need lots of energy to raise the temperature by 1c, help organisms survive?

Answer 4

The hydrogen bonds need a lot of energy to break apart as they absorb lots, therefore has a high specific heat capacity. Meaning the temperature stays quite stabl, meaning the organisms have a stable environment and there is no effect on the enymes for eg.

Question 5

What type of reaction occurs when water is added to break a bond in a molecule

Answer 5

Hydrolysis

Question 6

The phosphate group of a phospholipid that readily attracts water molecules

Answer 6

Hydrophilic

Question 7

Why is water vital to living organisms?

Answer 7

• Reactant
• Solvent
• Transports substances
• Controls temperature
• Habitat

Question 8

What is cohesion?

Why are water molecules cohesive?

Answer 8

The attraction between molecules of the same type

Water molecules are very cohesive because they are polar

Question 9

Describe a water molecule

Answer 9

One oxygen molecule attached to two hydrogen atoms. They share electrons therefore the negative hydrogen electrons are pulled forward on the hydrogen, leaving them with a slight positive charge. And negative on the oxygen from the unshared electrons. This makes water polar

Question 10

High specific heat capacity

Answer 10

The hydrogen bonds can absorb lots of energy, therefore can keep a stable environment for the organisms.
Useful as many cells are water

Question 11

How is water a solvent

Answer 11

Substances are mainly ionic, therefore the positive electrons attract to the negative polar electrons of the water and vise versa. Therefore the ions become completely surrounded by the water molecules and dissolve.

Question 12

Water has a high latent heat of evaporation

Answer 12

This means it takes a lot of energy to break the hydrogen bonds between the water molecules. So lots of energy is used up when water is evaporated. This is useful for cooling organisms.

Question 13

What reactions does water take place in?

Answer 13

Photosynthesis and hydrolysis reactions

Question 14

Why is water being a solvent important?

Answer 14

Most biological reactions take place in solutions making it pretty essential

Question 15

What substances does water transport

Answer 15

Glucose and oxygen around plants and animals

Question 16

Why is water important at controlling temperatures?

Answer 16

Helps cools surfaces and lower the temperature

Question 17

Water is a small molecule much lighter than co2 but remains a liquid at room temp, why?

Answer 17

Due to the hydrogen bonding between the water molecules, it takes alot of energy to increase the temperature of water and cause it to change states into a gas

Question 18

What happens when water freezes?

Answer 18

When water freezes the hydrogen bonds fix positions of the polar molecules slightly further apart than the average distance. This make a giant rigid lattice structure with oxygen at the center of the arrangement
resulting into the ice floating
Start to solidify and hydrogen bonds in the water molecules form crystal infrastructure which space molecules apart more evenly, making it less dense

Question 19

Cohesive properties in organisms

Answer 19

As water cohesive, they attract to eachother, therefore plants can draw up water by their roots and up xylem tissues of plants

Question 20

what and how is water got adhesive properties

Answer 20

This is where water molecules are attracted to other molecules as they have more charge. an example is washing your hands, the water doesnt run straight off.

Question 21

A property of cohesion and pros of it

Answer 21

Surface tension as the water molecules are more cohesive to each other than anything else around
This allows the top of water to be a habitat for ponskaters

Question 22

Why is water an important transport medium

Answer 22

it can dissolve many molecules

Question 23

At what temperature does the density of water start to decrease

Answer 23

4c

Question 24

Difference between adhesion and cohesion

Answer 24

A- attraction between two different molecules

C- acttraction between two of the same molecules

Question 25

Why dont hydrophobic molecules dissolve in water?

Answer 25

They have no polar charge and being pushed out of the water be waters cohesiveness