2.1.3-Amount of substance

Question 1

avogadros constant

Answer 1

-6.02 x 10 23
-of any substance

Question 2

define mole

Answer 2

-amount of substance that contains 6.02 x 10 23 particles

Question 3

define molar mass

Answer 3

gmol-1

Question 4

when is RAM RMM and RFM used

Answer 4

-element = RAM
-covalent compound or molecule= RMM
-ionic compound = RFM

Question 5

Kevin got mangoes
my darling chocolate

Answer 5

x1000
divide 1000

Question 6

molar gas volumes

Answer 6

-the volume per mole
of gas molecules
-at a tested temperature and pressure

Question 7

the ideal gas

Answer 7

-made up of particles in continuous random motion
-particles have position but zero volume
-collisions bw particles are completely elastic i.e no energy is lost
-there are no forces acting bw molecules

Question 8

amount of substance

Answer 8

the number of particles in a sample
unit mol

Question 9

describe the benefits for sustainability of developing chemical processes with high atom economy

Answer 9

-A reaction with a high atom economy ,it uses fewer natural resources and produces less waste
- so reactions with high atom economies are better for the environment
-products from an efficient reaction will be cheaper to produce.

Question 10

what does atom economy and percentage yield measure

Answer 10

atom economy-measures efficiency of a reaction

percentage yield-measure of how successfully reactants converted into products

Question 11

how to convert C into K

Answer 11

+273

Question 12

density mass and volume equation

Answer 12

density= mass
———–
volume

Question 13

dilution

Answer 13

lowering concentration of a solute
by adding more solvent to solution such as water

Question 14

potential errors in using a gas syringe

Answer 14

-gas escapes before inserted
-syringe sticks
-some gases such as carbon dioxide or sulphur dioxide are soluble in water do true amount of gas not measured

Question 15

how to increase accuracy in preparing solutions

Answer 15

1-use volumetric pipette as more accurate than a measuring cylinder because it has a smaller uncertainty

2-use teat pipette to make up to mark in volmetric flask to ensure volume of solution accurately measured and one dosen’t go over the line

Question 16

theoretical yield

Answer 16

maximum possible product if all reactanats converted to product

Question 17

stoichiometry

Answer 17

ratio of amount/moles each substance in balanced eq

Question 18

avogadro constant

Answer 18

number of particles in each mol of carbon-12

Question 19

experimental techniques when measuring
-mass
-volume of a solution
-gas syringe

Answer 19

mass
-use digital mass balance,importantn to use a blance with suitable resolution for experiment

volume of solution
-a measuring cylinder
-if making up a standard solution,should use volumetric flask

volume of gas produced
-gas syringe
-measure mass lost on balance

Question 20

under standard conditions ,gases and volatile liquids follow trends,what are they

Answer 20

-pressure proportional to temperature
-volume proportional to temperature
-pressure and volume are inversely proportional

Question 21

standard solution

Answer 21

-solution of known concentration
-prepared by dissolving a known mass of solid in solvent and make up to exact volume

Question 22

hydrated vs anhudrous substance

Answer 22

anhydrous-contains no water of crystillisation
hydrated-contains water of crystillisation

Question 23

Pressure

Answer 23

Pascal (Pa) kPa- Pa -x1000