Physical

Question 1

Methyl orange

Answer 1

0-3 red
3-6 orange
6-14 yellow

Question 2

Phenolphthalein

Answer 2

0-10 colourless

10-14 red

Question 3

Acid def

Answer 3

A substance that dissolved in water to produce hydrogen ions (H+)

Question 4

Litmus paper

Answer 4

0-4 red
5-8 purple
8-14 blue

Question 5

Acid + metal

Answer 5

Salt + hydrogen

Question 6

Acid+ metal carbonate

Answer 6

Salt + CO2 + water

When testing wait till no more bubbles form to show complete neutralisation

Question 7

Acid + metal oxide

Answer 7

Salt + water

Question 8

Acid + metal hydroxide

Answer 8

Salt + water

Question 9

Solubility

Nitrates

Answer 9

All

Question 10

Solubility

Chlorides

Answer 10

All but silver and lead

Question 11

Solubility

Sulfates

Answer 11

All but barium, calcium and lead 2

Question 12

Solubility

Sodium, potassium and ammonium salts

Answer 12

All

Question 13

Solubility

Sodium, potassium and ammonium carbonates

Answer 13

All

Question 14

Insoluble base + acid test

Answer 14

• heat acid
• add base a little at a time
• till excess
• filter (to remove access)
• hydrous? Heat till at least 2/3 of the water had left
• leave to crystallise in a warm place
  Remove crystals and then dry

Question 15

Soluble base + acid test

Answer 15

• aqueous solution of alkali into conical flask and add indicator
• add dilute acid until change in colour
• add powdered charcoal and shake to remove colour
• filter to remove charcoal
• obtain crystals from filtrate

Question 16

Preparation of insoluble salts

Answer 16

Precipitation reactions!

(Insoluble solid made by chemical reaction in an aqueous solution)

• mix 2 aqueous solution
• one of then contains +ve ion other
• ve ion
• filter
• with the filtrate wash with distiller water to remove traces of the solution formed
• leave to dry

Question 17

Make ammonia

Answer 17

Whenever ammonium salt reacts with an acid

Indicator needed to decide whether or not reaction is complete
- acid alkali titration

Question 18

Acid- alkali titration

Answer 18

To find given volume of acid required to react exactly with the given volume if alkali

• use pipette add 25cm3 of alkali solution into conical
• add few drops of indicator
• put acid into a burette and note initial reading
• add acid till change in colour
• not how much was added
• repeat without indicator but the exact volume

Question 19

Exothermic

Answer 19

Energy given out

Rise in temp

——–\______

^H = negative

Question 20

Endothermic

Answer 20

Energy taken in

Fall in temp

_____/———

^H = positive

Question 21

Measure heat change

Answer 21

Place acid into polystyrene cup
Record temp of acid
Tip excess powder into acid
Measure and record highest Reno reached by mixture

• rise in temp
• heat given out

Question 22

Heat given out equation

Answer 22

Mass of solution x specific heat capacity x temp rise

E = mc^T

Question 23

Bond energies

Answer 23

Energy required to break a bond

Question 24

Bond energy measured in…

Answer 24

Kj per mol

KJ/mol

Question 25

Breaking bonds

Answer 25

Takes in energy Endothermic process

Question 26

Making bonds

Answer 26

Gives out energy Exothermic process

Question 27

How to calculate /\ H

Answer 27

Bonds broken- bonds made

Question 28

Rate of reaction def

Answer 28

Rate = change of conc of reactant / time

Question 29

Factors there affect rate of reaction (3)

Answer 29

Conc of reactant Temp at which reaction takes place State of division

Question 30

Conc rates

Answer 30

Increasing conc increases no of particles in a given volume hence increasing the frequency of collisions This means there will be more successful collisions per second Same as increasing pressure

Question 31

Temp rates

Answer 31

Increased average kinetic energy of the reactant particles therefore more of the collisions will have the required activation energy needed to be successful

Question 32

State of division rates

Answer 32

Smaller the pieces the larger the surface area More particles exposed to other reactant More successful collisions per sec Most effective in powder form

Question 33

Effect of catalyst

Answer 33

Provides an alternate pathway for the reaction Has a lower activation energy than the original pathway Means that more of the collisions will have the necessary activation energy

Question 34

Catalyst def

Answer 34

A substance that increases the rate of a chemical reaction but is chemically unchanged at the end of the reaction

Question 35

Reaction that goes both ways

Answer 35

Reversible

Question 36

Example of a reversible reaction

Answer 36

``` Copper 2 sulfate crystals Hydrous and anhydrous Heating and adding water Water of crystallisation From white to blue with water ```

Question 37

2nd example of reversible reaction

Answer 37

Heating ammonium chloride White solid crystals -> colourless gases NH4Cl -> HCl + NH3 The gases rise and cool to form back

Question 38

Dynamic equilibrium

Answer 38

If reaction reversible is carried out in a closed container then it is possible for the reaction to reach a position of dynamic equilibrium When rate if forward is equal to rate of backward Amounts of reactants and products remain CONSTANT Properties relying on amounts of reactants/ products remain constant (colour or pressure)

Question 39

Shift the position of equilibrium

Answer 39

To the right | To the left

Question 40

Equilibrium increase pressure

Answer 40

Shifts in direction that produces the smaller number of molecules of gas

Question 41

Equilibrium increase in temp

Answer 41

Moves in endothermic direction

Question 42

Equilibrium decrease in temp

Answer 42

Moves in Exothermic direction

Question 43

Equilibrium model answers | Temperature

Answer 43

The equilibrium shifts to the (left/right) because the (forward/backward) reaction is Exothermic

Question 44

Equilibrium model answer | Pressure

Answer 44

The equilibrium shifts to the (left/right) because there are fewer molecules of gas in the (left/right)

Question 45

Equilibrium model answer | Adding or removing substances

Answer 45

The equilibrium shifts to the (left/right) because the (forward/backward) reaction uses/produces the _____

Question 46

Equilibrium | Increasing temp will favour the....

Answer 46

Endothermic reaction because this reaction needs heat to occur Decreasing will favour Exothermic because less heat means that the endothermic reaction can't happen as much