Water unit

Question 1

What % of the earth is water

Answer 1

= +70% and humans are made of 72% water

Question 2

What is water (qualities)

Answer 2

• Polar molecule
• Discrete molecule compound
• At 25 deg water is clear, colourless and odorous liquid
• Freezes @ 0 deg and boils @ 100 deg

Question 3

What does polar mean

Answer 3

= uneven distribution of charge

Question 4

How does water break apart ionic compounds

Answer 4

-> water = universal solvent b/c polar molecule breaking compound into +ve and -ve ions

Question 5

Properties of water

Answer 5

• latent heat
• specific heat capacity
• solid ice is less dense than liquid water

Question 6

What is latent heat

Answer 6

= a measure of amount of heat energy required 2 change the state of a substance
- latent heat of fusion = energy required 2 change solid 2 liquid
- latent heat vaporation = energy required 2 change liquid 2 gas

Question 7

What is specific heat capacity

Answer 7

= measure of energy required 2 raise the temp of 1g of a substance by 1 deg
- specific heat capacity of water = 4.18 J^-1 deg cel^-1

Question 8

Specific heat capacity equation

Answer 8

Q =mc(delta)T

Question 9

What is a solvent

Answer 9

= a liquid that dissolves a substance

Question 10

What is a solute

Answer 10

= substance being dissolved by the solvent

Question 11

What is a solution

Answer 11

= solvent and solute mixture

Question 12

What are the different type of solutions

Answer 12

• Saturated solution
• Unsaturated solution
• Supersaturated solution

Question 13

Expressing solution Concentration

Answer 13

= concentration (g/L) = mass / volume

Molarity = concentration (mol/L) = mol / volume

Question 14

What is concentration

Answer 14

= amount of solute per volume of solvent

Question 15

What does molarity mean in reference to mols

Answer 15

= number of mol

Question 16

Bronsted lowry acid definition

Answer 16

-> acids = proton donors

Question 17

Bronsted lowry base definiton

Answer 17

-> base = proton acceptors

Question 18

What are some common acids

Answer 18

• HCl
  -HNO(3)
• H(2)SO(4)
• CH(3)COOH

Question 19

What are some common bases

Answer 19

• NaOH
• NH(3)
• Na(2)CO(3)

Question 20

What is the conjugate base

Answer 20

= same as the starting acid minus H+

Question 21

What is the conjugate acid

Answer 21

= same as the starting base plus H+

Question 22

Common acid + “x” reactions

Answer 22

• Acid + metal carbonate -> salt + water + CO2
• Acid + reactive metal -> salt + hydrogen
• Acid + metal hydroxide -> salt + water

Question 23

What is a salt

Answer 23

= an ionic compound t/f made up of a metal + non metal

Question 24

What is a strong acid

Answer 24

They donate protons easily and completely ionise in solutions

Question 25

Examples of strong acids

Answer 25

HCl, HNO(3),H(2)SO(4)

Question 26

What is a weak acid

Answer 26

They x donate protons easily + partially ionise in solutions

Question 27

Examples of weak acids

Answer 27

CH(3)COOH, HCN,HNO(2)

Question 28

What factor does 1 jump in the pH scale have

Answer 28

-> each 1 unit change in the pH scale corresponds to a 10 fold change in H^+ ions

Question 29

How to calculate pH

Answer 29

equation: H = -log [H^+]
- [H^+] is the concentration of hydrogen ions. The more H^+, the lower the pH, the more acidic

Question 30

How to calculate [H^+]

Answer 30

equation : [H^+] = 10^(-pH)

unit = M / molL^-1