PHYSICAL - AMOUNT OF SUBSTANCE Flashcards

1
Q

Relative atomic mass

A

the average mass of an atom of an element relative to one twelfth of the mass of an atom of carbon-12.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Relative molecular mass

A

Ratio of the mass of 1 molecule to 1/12 of the mass of carbon-12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Avogadro’s constant

A

6.02x10^23

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Equation linking concentration and volume
amount

A

amount(mol/g) = conc x vol
cm3/1000 = dm3
conc = mass/volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Equation linking mass and Mr

A

mass = mol x Mr

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Titration calculation
0.25dm3 of a solution of CuSO4 weighs 47g. Calculate conc in mol dm-3:

A

Mr of CuSO4 = 159.6
mol = 47/159.6 = 0.294mol
0.294/0.25 = 1.18moldm-3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Back titration
A metal carbonate, M2CO3 reacts with HCl -> M2CO3 + 2HCl –> 2 MCl + CO2 + H2O. 4.5g M2CO3 dissolved to make a 250cm3 solution - 25cm3 of this was neutralised by 28.9cm3 of 0.148moldm-3 HCl.

A
  1. Calc mol of HCl in 28.9cm3 of 0.148moldm-3 HCl:
    28.9/1000 x 0.148 = 4.28x10-3 mol
  2. Calc mol of M2CO3 that reacted with this HCl
    (4.28x10-3)/2 = 2.14x10-3mol
  3. Calc mol of M2CO3 in the 4.5g sample
    2.14x10-3 x 10 = 0.0214mol
  4. Calculate RFM of M2CO3
    Mr = mass/mol
    4.5 / 0.0214 = 150.3
    150.3+12+(16x3) = 210.3 Mr
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Ideal gas equation

A

PV = nRT
P = pressure (Pa) KPa -> Pa = x1000
V = vol (m^3) cm3 -> m3 = /1000000
n = mol
R = gas constant
T = Kelvin (K) °C -> K = +273

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Empirical formula

A

Simplest whole number ratio of atoms of each element in a compound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Molecular formula

A

Actual number of atoms of each element in a compound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

EF calculation

A
  1. Divide mass/% of element by its Ar
  2. Work out simplest ratio
  3. Formula
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

MF calculation

A
  1. Divide actual Mr of compound by Mr of EF
  2. Multiply EF by answer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Hydrated compounds

A
  1. Mass/atomic mass
  2. Ratio
  3. Formula
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Atom economy

A

(Mr of useful product/Mr of all products) x100
Efficient processes: High AE, important for sustainable development as less waste produced and less natural resources used
Wasteful products can be sold for profit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly