solubility

Question 1

what is a solute

Answer 1

a gas or solid that dissolves in a liquid, called the solvent

Question 2

what are the solubility rules for ionic compounds in water

Answer 2

Solubility rules for ionic compounds in water:
Common sodium, potassium and ammonium compounds are soluble
* All nitrates are soluble
* Common chlorides are soluble, except those of silver and lead (Il)
* Common sulfates are soluble, except for those of barium, calcium and lead (Il)
* Common carbonates are insoluble, except for those of sodium, potassium and ammonium
* Common hydroxides are insoluble except for those of sodium, potassium and calcium (calcium hydroxide is slightly soluble).

Question 3

what are the solubility rules for ionic compounds in water (name the soluble ones)

Answer 3

Solubility rules for ionic compounds in water:
Common sodium, potassium and ammonium compounds are soluble
* All nitrates are soluble
* Common chlorides are soluble, except those of silver and lead (Il)
* Common sulfates are soluble, except for those of barium, calcium and lead (Il)

Question 4

what are the solubility rules for ionic compounds in water (name the insoluble ones)

Answer 4

• Common carbonates are insoluble, except for those of sodium, potassium and ammonium
• Common hydroxides are insoluble except for those of sodium, potassium and calcium (calcium hydroxide is slightly soluble).
• Common chlorides are soluble, except those of silver and lead (Il)
• Common sulfates are soluble, except for those of barium, calcium and lead (Il)

Question 5

what is solubility

Answer 5

the measure of how much a solute can dissolve in a certain amount of solvent. it is measured in grams per 100g (or 100cm^3) of water

Question 6

when can you describe a solid as soluble?

Answer 6

if it dissolves in a particular solvent

Question 7

what does a solvent and solute make together

Answer 7

a solution

Question 8

what is a saturated solution?

Answer 8

one in which no more solute can be dissolved in the solvent (when more solute is added it simply sinks to the bottom)

Question 9

what is a solvent?

Answer 9

a substance that dissolves another substance, called a solute, to form a solution

Question 10

what is a supersaturated solution?

Answer 10

when an object is heated up and cooled slowly so that added crystals grow

Question 11

what does a solubility curve show? what does the actual curve show?

Answer 11

what mass of a solvent will dissolve in a solvent at a given temperature . the curve shows the no. grams of solute in a saturated solution contaiing 100ml or 100g of water at a certian temp

Question 12

what does an amount of solute above/below the solubility curve indicate?

Answer 12

below-unsaturated at a certain temp
above-supersaturated

Question 13

what does it mean if the solubility curve moves up/down

Answer 13

if it moves down it is likely the solute is a gas but if it is a solid it will move upwards

Question 14

what happens if a solution is dissolved in water but cooled down (supersaturated)

Answer 14

it will come out of the solution/precipitate - not all would stay dissolved???

Question 15

what is concentration?

Answer 15

the measure of the number of particles dissolved in a given volume

Question 16

describe conc. in terms of acid in a bottle

Answer 16

if there are lots of acid particles and fewer water molecules, it is concentrated, if not it is dilute

Question 17

what is conc. measured in?

Answer 17

mol/dm^3 or m (Molar)

Question 18

what is Molar

Answer 18

the number of moles of a substance per 1 dm^3 of the solution it’s in

Question 19

what is dm^3 to cm^3

Answer 19

10^3cm3 = 1 dm3
1cm3 x 1000 = 1dm3

Question 20

describe the difference between conc. and strength.

Answer 20

strength is the extent to which an acid/alkali can dissociate (positive and negative bits break off) to produce H+ and OH- ions respectively. this si measured in pH. conc is the no of particles dissolved in a given volume

Question 21

does conc. increase/decrease during evaporation?

Answer 21

it increases because the water particles evaporate but the solid particles stay

Question 22

what is the equation linking moles, concentration, volume

Answer 22

moles = concentration x volume
n = cv
(mol) = (mol/dm3) x (dm3)

Question 23

what is the conversion between g/dm3 and mol/dm3

Answer 23

g/dm3 = mol/dm3 x Mr

Question 24

what is the equation linking moles, mass, and Mr?

Answer 24

n = mass/Mr
Mr x moles = mass

Question 26

what is the equation linking n,c,v with changing, v/c

Answer 26

n1=n2 c1 x v1 = c2 x v2 v2 = c1 x v1/c2

Question 27

what is conc(gdm3)?

Answer 27

Mr x conc (mol/dm3)

Question 28

what is the equation linking moles, conentration, colume?

Answer 28

moles/volume (dm3) = conc (mol/dm3)

Question 29

what is the gas equation?

Answer 29

n=v/24dm3 or vol in cm3/2400

Question 30

give me a step by step of titration in order to make a salk

Answer 30

1. use a pipette to put exactly 25 cm 3 of HCl (an acid) into a conical flask which is on a white tile 2. take your solution of calcium hydroxide (alkali) and pour it into a burette. Note the starting volume. 3. add a few drops (2-3) of a binary indicator, eg.g, phenolphthalein and slowly add the calcium hydroxide solution into the acid until the endpoint is reached when the indicator turns from colourless to pink 4. repeat the experiment without the indicator (note volume of alkali required for neutralisation) 5. once the solution is neutral, use a Bunsen burner to evaporate half of the water until the solution is saturated 6. allow to cool and crystalise 7. filter the solid calcium chloride 8. pat the calcium chloride dry with filter paper 9. transfer into a desiccator which is similar to an airtight container

Question 31

give me a step by step of titration in order to find the unknown conecntration

Answer 31

1. use a pipette to put exactly 25 cm 3 of HCl (an acid) into a conical flask which is on a white tile 2. take your solution of calcium hydroxide (alkali) and pour it into a burette. Note the starting volume. 3. add a few drops (2-3) of a binary indicator, eg.g, phenolphthalein and slowly add the calcium hydroxide solution into the acid until the endpoint is reached when the indicator turns from colourless to pink 4. repeat until concordant results (0.2 cm3) results obtained 5. calculate agreave titre (av. change in volume)

Question 32

what does an acid and metal hydroxide make?

Answer 32

acid+ metal hydroxide = salt + water

Question 33

what does an acid and metal make?

Answer 33

acid+ metal hydroxide = salt + hydrogen

Question 34

what does an acid and metal carbonate make?

Answer 34

acid+ metal carbonate = salt + water + carbon dioxide

Question 35

what is an acid?

Answer 35

a proton donor (A species that donates H* ions (protons))

Question 36

what is a base

Answer 36

a proton acceptor (A species that accepts H* ions (protons))

Question 37

what is a salt?

Answer 37

A compound where the H* from an acid has been replaced by a metal or other positive ion

Question 38

what is solubility?

Answer 38

A measure of the maximum amount of solute (in gl that can be dissolved per 100g of solvent

Question 39

what is a saturated solution?

Answer 39

A solution in which no more solute can be dissolved

Question 40

what is crystalisation?

Answer 40

* A process whereby solid crystals form from a cooling solution because the amount of dissolved solid was greater than the solubility at a lower temperature

Question 41

what colour does litmus go?

Answer 41

red in acids, purple in neutral solutions, blue in alkaline solutions

Question 42

what colour does methyl orange go?

Answer 42

red in acidic solutions, yellow in neutral and alkaline solutions

Question 43

what colour does phenolphthalein go?

Answer 43

colourless to pink (acid-alkaline)

Question 44

what is the reaction between a base and an acide

Answer 44

a neutralisation reaction

Question 45

what can Neutralisation reactions in aqueous solutions also be shown as?

Answer 45

ionic equation in terms of H+ and OH- ions (H+ + OH- -> H2O)

Question 46

what happens in a neutralisation reaction?

Answer 46

the OH ions are equal to the concentration of hydrogen ions

Question 47

awhat cann all acids do?

Answer 47

ionise/ dissociate in solution which means splitting up a hydrogen ion and another ion e.e.g, HCl -> H+ + CL-

Question 48

waht does acid strength mean?

Answer 48

what proportion of the acid molecules ionise in water

Question 49

what is the difference between weak and strong acids?

Answer 49

stong acids almost completely ionise in water so they dissociate to release h+ ions whereas weak acids don't fully ionise.

Question 50

wht is the ionisaiton of a weak acid?

Answer 50

a reversible reaction, which sets up an equilibrium. only a few of the acid particles release H+ ions to the equilibrium lies far to the left

Question 51

how does concentration affect PH?

Answer 51

if the conc of H+ ions increases by a factor of 10, the pH decreases by 1 so if conc increases by 100 (10x10) the pH decreases by 2 (1+1)

Question 52

what is the difference between a soluble and insoluble salt?

Answer 52

when the two solutions are mixed, a salt will form a precipitate (insoluble) or just a form in solution (soluble salt)

Question 53

how do you make an insoluble salt?

Answer 53

using a precipitation reaction where you pick two soluble salts and react them together to make an insoluble salt

Question 54

how do you make a soluble salt?

Answer 54

using an acid and an insoluble base