7 CHEMICAL CALCULATIONS (mol) Flashcards

1
Q

how to calculate relative atomic mass (Ar)

A

js take it from the periodic table
[(% x mass) of each isotope added up]

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

how to calculate relative molecular mass (Mr)

A

all the Ar added up
O = 16.0 –> Ar
O3 = 16.0x3=48 –>Mr

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

how to calculate percentage composition of a compound

A

Ar of the element / Mr of the compound
% of H in H2O
H=1x2
O=16.0
2/16+2 = 1/9

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

calculate percentage composition of water in a compound

A

its the same as b4 js tat now H2O is considered 1 element
5(H2O) = 5 x 18
5(O) = 5 x 16

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

how much is one mole

A

6.02 x 10^23

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

relationship between
mass(g), number of moles(mol), molar mass(Ar,Mr)

A

its the same as the dst triangle
mass(g) on top
moles (mol) molar mass (Ar.Mr)

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

what is the empirical formula for

A

the empirical formula of a compound is the simplest formula which shows the ratio of the atoms of the different elements in the compounds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

formula for empirical formula

A
  1. mass(g) of each element (given in qn)
  2. molar mass(Ar,Mr) of element (given in period table)
  3. no. of moles(mol) DST it g/Mr
    4.Mole ratio (divide each value by the smallest value) from 3.
  4. simple ratigo it
How well did you know this?
1
Not at all
2
3
4
5
Perfectly