AQUATIC CHEM QUIZ 1

Question 1

Indicator for total acidity

Answer 1

Titration with base and phenolphthalein, both strong and weak acid neutralised

Question 2

Indicator for free mineral acid

Answer 2

Missall orange only strong acids neutralise

Question 3

Defined the effective concentration of a species

Answer 3

The species chemical potential depends on the activity of a real solution in the same way it would depend on concentration for an ideal solution

Question 4

Define alkalinity

Answer 4

Alkalinity is the capacity of water to accept protons (H+ ions), the ability of natural water to neutralise acid

Question 5

Buffer solution

Answer 5

Maintains a constant hydrogen iron concentration

Question 6

How can a solution have a high acidity but weak acids present

Answer 6

The solution has the potential to create hydrogen ions yet it has low acidic properties because it has not yet done so

Question 7

Name the three layers in a schematic of a static water body

Answer 7

Epilimnion (Relatively high dissolved oxygen, chemical species found in oxidised forms)

Thermocline

Hypolimion (low dissolved oxygen, Chemical species found in reduced form)

Question 8

Define humidity

Answer 8

The amount of water vapour in the air expressed as a percentage of the amount needed for saturation at the same temperature

Question 9

Define polluted water

Answer 9

One harmful substances example chemicals or micro organisms contaminate a water body leaning to a degraded water quality

Question 10

Define hard water

Answer 10

High on dissolved minerals especially calcium and magnesium, soap reacts with the calcium to form a scum, more soap is required for washing therefore wasteful

Question 11

How is water hardness related to alkalinity

Answer 11

The main source of alkalinity is from limestone (calcium carbonate rocks, CaCO3)

Question 12

List for properties of water and provide the significance to these properties

Answer 12

Excellent solvent- capable of dissolving more substances than any other liquid known as universal solvent

Good for transportation- transports nutrients and waste products making biological processes possible and aqueous solutions

high surface tension- allowing rain to move as drops

Question 13

How does water interact with Environmental spheres

Answer 13

Hydrosphere provides water for biosphere to function grow and live example animals
Lithosphere dash weathering agent helps break down rock to mix with biosphere soil

Atmosphere moves water (hydrosphere )all over Earth

Question 14

Kinetic energy of water molecules at freezing versus boiling

Answer 14

Kinetic energy is low at freezing temperatures that hydrogen bonds hold the molecules in place with respect to one another ice

Temperature above freezing but boiling kinetic energy is such that the hydrogen bonds keep breaking and reforming with different molecules- liquid water

Question 15

Properties of water

Answer 15

Colourless odourless tastless

covers 70% of Earths surface Vitally important great solvent high surface tension high heat of evaporation

Question 16

What holds water together

Answer 16

Hydrogen bonds a type of dipole dipole attraction between molecules resulting from a hydrogen atoms covalently bonded to a very electronegative atom N, O or F and another electronegative atom

Question 17

Latent heat

Answer 17

The heat required to convert a solid into a liquid/vapour without a temperature change this provides energy to power a massive storms

Question 18

Limnology

Answer 18

Study of inland waters freshwater and saline water example lakes rivers streams wetlands

Question 19

Oceanology

Answer 19

Study of the characteristics of water in oceans

Question 20

Water stress

Answer 20

When water resources are insufficient for their needs in that country