4.2 non exam qs

Question 1

Whats sulfuric acids formula

Answer 1

H2SO4

Question 1

whats hydrochloric acids formula

Answer 1

HCl

Question 2

Whats nitric acids formula

Answer 2

HNO3

Question 3

Whats phosphoric acids formula

Answer 3

H3PO4

Question 4

Whats carbonic acids formula

Answer 4

H2CO3

Question 5

how is something an acid

Answer 5

acids release h+ ions in aqueous solutions

Question 6

Metals below hydrogen wont do what?

Answer 6

react with dilute acid but can react with concentrated acid

Question 7

metal + acid —>

Answer 7

salt + hydrogen

Question 8

which is in excess and which is limiting reactant in the salt + acid equation?

Answer 8

metal is in excess,, acid is the limiting reactant

Question 9

metal oxide + acid —>

Answer 9

metal salt + hydrogen

Question 10

metal carbonate + acid –>

Answer 10

metal salt + water + CO2

Question 11

whats the method to making salt?

Answer 11

using a measuring cylinder, measure 25cm of acid/a into a beaker of cone

warm the acid

add excess metal/ metal oxide/ metal carbonate until more dissolves and some solid is left at the bottom

filtration - using filter paper and funnel and conical flask to filter out excess solid

pour into evaporating basin, evaporate until crystals form on rim, sols now saturated, leave basin on window sill 4 water to evporate and crystals to appear, pat dry w/ filter paper

Question 12

how can soluble salts be made?

Answer 12

from reacting insoluble bases w/ acids

Question 13

what is a base

Answer 13

a substance that neutralises acid ( metal oxide, metal carbonate etc)

Question 13

base + acid —>

Answer 13

salt + water

Question 14

what is a strong acid

Answer 14

a strong acid will completely ionise to produce H+ ions

Question 15

whats THE neutralisation reaction equation?

Answer 15

H+ + OH- –> H2O

Question 16

what does a weak acid do

Answer 16

partially ionises releasing few H+ ions in aqueous solution

Question 17

whats a dilute acid
whats a concentrated acid

Answer 17

a small amount of acid (H+ IONS) per unit volume of solution

bigger amount of acid per unit volume of solution

Question 18

how does the strength of an acid relate to rate of reaction

Answer 18

a strong acid is more reactive than a weak acid of the same concentration

Question 19

how can an acid be both strong and dilute

Answer 19

acids dilute when theres a small amount of acid per unit volume but strong because it completely ionises to form H+ ions in water

Question 20

what is pH

Answer 20

a measure of H+ ion concentration

Question 21

what happens to H+ ion concentration as pH increases

Answer 21

H+ ion concentration decreases (inverse scale)

Question 22

whats a pure substance

Answer 22

a single element or compound not mixed with any other substance

Question 23

pure elements and compounds do what

Answer 23

melt and boil at specific temperatures

Question 24

what do impurities do in regards to state change

Answer 24

lower melting points , increase melting ranges and they increase boiling points and cause a range of boiling temperatures

Question 25

whats a formulation

Answer 25

a mixture that has been designed as a useful product

Question 26

whats a complex mixture

Answer 26

each chemical has a specifc purpose

Question 27

how are formulations made

Answer 27

by mixing the components in carefully measured quantities to ensure that the product has the required properties

Question 28

what are examples of formulations

Answer 28

fuels, cleaning agents, paint, medicine , alloys , fertilisers , some food

Question 29

how to know if the mixtures a formulation

Answer 29

materials a mixture, material serves a purpose, components in mixture are measured in specific amounts

Question 29

whats the stationary phase

Answer 29

a solid or liquid, eg the chromatography paper

Question 30

whats the mobile phase

Answer 30

a liquid or gas, (eg a solvent)

Question 31

what does separation of components in a mixture depend on?

Answer 31

the distribution of substances between the two phases

Question 32

substances w/ a greater attraction to the paper do what?

Answer 32

move less distance

Question 33

substances with less solubility in the solvent do what

Answer 33

move less distance

Question 34

what are the two ways of testing for the positive ion

Answer 34

flame test, sodium hydroxide test

Question 35

what are the 3 ways of testing for the negative ion

Answer 35

carbonate test sulfate test, halide test

Question 36

what are the results of the sodium hydroxide test for magnesium, calcium and aluminium, copper, iron (III) AND Iron (ii)

Answer 36

mag- white ppt cal - white ppt aluminium- white ppt, redissolves in excess NaOH so forms colourless solution copper- blue ppt iron (ii) - green ppt iron (iii) -brown ppt

Question 37

what is the carbonate test

Answer 37

add acid (whichever) to the solution, observe effervescence and collect gas with a pipette and place into limewater to test if it goes cloudy

Question 38

what colour does chloride, bromide and iodide turn in the halide test?

Answer 38

cl -white br- cream i- yellow

Question 39

what are the advantages of instrumental analysis

Answer 39

theyre accurate, sensitive and rapid and are particularly useful when the amount of a sample is very small making them more useful compared to chemical analysis

Question 40

how does flame emission spectroscopy work

Answer 40

the sample is put into a flame and the light given out is passed through the spectroscope, the output is a line spectrum that can be analysed to identify he metal ions in the sol and measure their concentration specific emission line spectra are produced by specific metal ions

Question 41

whys the flame emission spectroscopy better than flame testing?

Answer 41

it can identify the metal ions present in a mixture and determine their concentrations ( more conc = more intense line spectre)