Molecular Formula

Question 1

What does M stand for and what is it?

Answer 1

It is the molar mass (gmol-1) it can be found out using Ar(x)+Ar(b)
(Ar is found on the periodic table)

Question 2

What does n stand for and how can it be found?

Answer 2

Number of moles(mol)
It can be found using n=m(mass g)/M(gmol-1)
n=N/NA

Question 3

What does N stand for and how is it found

Answer 3

Number of particles
If we know the mole(n)
N=nxNA

If we know the mass(m)
1.n=m/M
2.N=nxNA

Question 4

What does m stand for and how can it be found

Answer 4

It is mass(g)
If we know the number of particles (N)
1.n=N/NA
2.m=nxNA
If we know the mole(n)

m=nxNA

Question 5

what is NA

Answer 5

Advogadros constant (mol-1)
6.02x10^23

Question 6

Empirical formula

Answer 6

Composition/ mass
Then divide by the smallest answer

Question 7

Alkane general formula:

Answer 7

CnH2n+2

Question 8

Alkene general formula:

Answer 8

CnH2n

Question 9

Alkyne general formula:

Answer 9

CnH2n-2

Question 10

when asked for the amount of substance

Answer 10

mol
n=N/Na

Question 11

when asked for the number of molecules

Answer 11

N=nxNa

Question 12

when asked for the number of atoms

Answer 12

N=(how much elements there are ex. H2O=3)xnxNa

Question 13

Ar formula

Answer 13

(no. of pt)x(abundance)/100

Question 14

molecular formula

Answer 14

(gmol-1 that’s given in the question )/molar mass
then use the answer to times the empirical formula with

Question 15

percentage composition

Answer 15

(how much of the element) x the no. found on pt x 100