Chemistry (Neutralisation and Chemical Kinetics)

Question 1

Who made the Arrhenius Model?

Answer 1

Svante Arrhenius (1897)

Question 2

What is an acid?

Answer 2

Substances that contain the hydrogen ion.

Question 3

What is a base?

Answer 3

Substances that contain the hydroxide ion.

Question 4

Who invented the bronsted-lowry model?

Answer 4

Johannes Nicolaus Bronsted and Thomas Martin Lowry (1925)

Question 5

What is the Bronsted-Lowry Model?

Answer 5

That acids are substances that donate protons, bases are substances that accept protons.

Question 6

What defines a strong acid and a strong base?

Answer 6

Strong acids are acids that are strong electrolytes.
Strong bases are bases that are strong electrolytes.
Weak acids are acids that are weak electrolytes.
Weak bases are bases that are weak electrolytes.

Question 7

What does the pH of a solution mean?

Answer 7

A way of assigning a simple numerical value to represent hydrogen ion concentration.

Question 8

State the disassociation of water

Answer 8

To a very small extent, water disassociates into ions in pure water.

Question 9

What is a buffer solution?

Answer 9

A solution that can resist small changes in pH.

Question 10

How are buffer solutions prepared?

Answer 10

Solution of weak acid mixed with the salt of a weak acid.
Solution of weak base mixed with the salt of a weak base.

Question 11

What does adding acid to a buffer do?

Answer 11

Usually, an acid would decrease the pH, although since the buffer favours the formation of acid, using up the hydrogen ions, the pH increases, and so counteract the partial decrease, creating a neutral overall pH. However, the overall change would be a slight decrese in pH.

Question 12

What does adding base to a buffer do?

Answer 12

Usually, a base would increase pH, although the buffer favours the formation of hydrogen ions, and so favours the production of base increasing the H+ concentration. The pH would initially increase and the production of the base would decrease pH and so the pH would be minimsed till almost neutralisation. (Although still a bit basic).

Question 13

What is buffer capacity?

Answer 13

The minimum amount of acid or base that can be added to a buffer solution before it radically changes pH.

Question 14

What are 4 uses of buffers?

Answer 14

• House-hold products
• Calibrating pH meters
• Regulation of blood pH
• Maintaining ocean pH levels

Question 15

How is a pH measured? Using what?

Answer 15

An electronic device that has a plug-in-probe. This probe is immersed in the solution and the pH is displayed on the meter.

Question 16

What is the formula for finding pH from hydrogen ion concentration?

Answer 16

• log_10(c(H+))

Question 17

What is the formula for finding hydrogen ion concentration from pH?

Answer 17

10 ^ -pH
Where pH is just the value on the pH scale.

Question 18

What is Litmus paper? And how do the two types work?

Answer 18

Litmus paper is small strips of red and blue paper that changes colour in solutions of different pH.

• Red Litmus paper will stay red in an acidic solution but will turn blue if put in basic solution.
• Blue litmus paper will stay blue in basic solution but will turn red in acidic solution.

Question 19

What are indicators?

Answer 19

Synthetic dyes that are designed to change colours in solutions of different pH.

Question 20

What is universal indicator?

Answer 20

A mixture of different indicators that give a range of colours across the pH scale. A few drops can determine the pH of any solution.

Question 21

What are gases in terms of motion?

Answer 21

Particles that are in constant random motion.

Question 22

What does it mean that gases have elastic collisions?

Answer 22

There is no net loss of energy from the collisions.

Question 23

What does gas volume have to do with containers?

Answer 23

Gas particles are samll and the total volume occupied by gas molecules is negligable relative to the total volume of their container.

Question 24

Do ideal gases have intermolecular forces?

Answer 24

No, gas molecules are non-polar

Question 25

What is the relationship between average kinetic energy of gas particles and absolute temperature?

Answer 25

The average kinetic energy of gas particles is proportional to the absolute temperature of the gas, and all gases at the same temperature have the same average kinetic energy. (Temperature is a measure of average kinetic energy expressed).

Question 26

What does Charles Law state?

Answer 26

Volume is directly proportional to temperature.

Question 27

What does Boyles Law state?

Answer 27

Volume is inversely proportional to pressure.

Question 28

What is the relationship between pressure and temperature?

Answer 28

Directly proportional to temperature assuming volume is kept constant.

Question 29

What does the rate of reaction tell us?

Answer 29

The speed at which reactants are chemically converted into products.

Question 30

List 4 things needed to measure the rate of reaction.

Answer 30

• Change in temperature
• Change in pH
• Change in pressure
• Production of gases

Question 31

What is the importance in measuring the rate of a chemical reaction?

Answer 31

• Efficiently producing a substance
• Monitoring the effects of certain substances on a chemical system
• Waste treatment: How quickly impurities can be removed.

Question 32

State the 3 rules of the collision theory

Answer 32

1. Two reactants must collide
2. Must collide with sufficient energy
3. Must collide with correct orientation