amount of substance (foundations in chemistry)

Question 1

what is amount of a subtance

Answer 1

the number of particles in a substance . the unit = mol and one mol is the amount of a substance that contains 6.02 x 10 ^23 particles

Question 2

what is the mass of one mol of magnesium

Answer 2

24.3g

Question 3

what is the unit for molar mass

Answer 3

g mol -1

Question 4

what is molecular formulae

Answer 4

the number and type of atoms of each element in a molecule eg cl2

Question 5

what is emperical formulae

Answer 5

a formula that shows the simplest whole number ratio of the number of atoms of each element in a compound eg p4o10 = p2o5

Question 6

what is relative formula mass

Answer 6

the weighted mean mass of the formula unit of a
compound compared with 1/12th the mass of an atom of carbon 12

Question 7

flouride formula

Answer 7

F-

Question 8

nitrate formula

Answer 8

NO3-

Question 9

hydrogen carbonate

Answer 9

HCO3-

Question 10

carbonate

Answer 10

CO3 2-

Question 11

sulfide

Answer 11

S2-

Question 12

sulfate(VI)

Answer 12

SO4 2 -

Question 13

1 ton in grams

Answer 13

1,000,000

Question 14

1 mg in grams

Answer 14

0.001g

Question 15

What is molar mass

Answer 15

Molar mass of a substance is the mass of one mol of a substance and it has units g mol ^-1

Question 16

1 cm^3 in ml

Answer 16

1 ml

Question 17

1 Dm^3 in cm^3

Answer 17

1000cm^3

Question 18

1 dm^3 in m^3

Answer 18

0.001 (/1000)

Question 19

Equation linking moles , conc and vol with units

Answer 19

Moles (n) = concentration (mol dm ^-3) x volume (dm^3)

Question 20

What is the concentration of a solution

Answer 20

The concentration of a solution is the amount of solute in moles dissolved in 1 dm^3 of solution

Question 21

What is the assumption of volume of gases

Answer 21

All gases occupy the same volume of gas per mol at a fixed temp and pressure

Question 22

What is the molar gas volume

Answer 22

24.0 dm^3 mol^-1 ( at 20c and 1 atm ) so at RTP 1 mol of gas molecules has a volume of 24dm^3

Question 23

What is the ideal gas equation and units

Answer 23

P(pa)V(m3) = n(moles) R(8.314Jk-1 mol-1) T(K)

Question 24

1 atm in pa

Answer 24

10^5 pa

Question 25

25 c in K

Answer 25

298 K

Question 26

0 c in K

Answer 26

273 K

Question 27

How to convert kelvin (K) to degrees

Answer 27

-273 and vice versa

Question 28

What is a neutralisation reaction

Answer 28

Acid + base - salt + water

Question 29

How can you increase atom economy

Answer 29

Finding a use for all the products , creating no waste

Question 30

Why would a reaction not have 100% yield

Answer 30

Reversible, so won’t go to completion , some may be lost when it is separated from the reaction mixture , some of the reactants may react in ways different to the expected reaction(side reactions)(impurities)

Question 31

What is the equation for percentage yield

Answer 31

Actual yield / theoretical yield x 100

Question 32

What is the equation for atom economy

Answer 32

Total Mr of desired product / sum of total mrs of all reactant x 100

Question 33

Why is atom economy important

Answer 33

Profit , waste , sustainability