Atoms Ions And Compounds

Question 1

Isotopes

Answer 1

Atoms of the same element with different numbers of neutrons and a different mass

Question 2

Cations

Answer 2

+ve

Question 3

Anions

Answer 3

-be

Question 4

For mass why not just add no. Protons and neutrons

Answer 4

Strong nuclear force is holding protons and neutrons comes at the expense of a loss of a fraction of their mass (mass defect)

Question 5

Standard mass for atomic mass

Answer 5

U= 1/12 mass of an atom of carbon 12

Question 6

Relative isotopic mass

Answer 6

The mass of an isotope relative to 1/12 the mass of an atom of carbon 12

Question 7

Relative atomic mass

Answer 7

The weighted mean mass of an atom of an element relative to 1/12 the mass of an atom of carbon 12
Takes account of abundance and isotopic mass

Question 8

How does a mass spectrometer work

Answer 8

Sample placed in Massbach samplers vaporised then ionised to form positive ions Ions accelerated- heavier move slower and are deflected less. Ions separated. Detected on mass spectrum as a mass to charge ratio. Each ion adds a signal, higher abundance=greater signal

Question 9

Binary compound

Answer 9

Contain two elements only

Question 10

Manganate(vII)

Answer 10

MnO4-

Question 11

Sulfite

Answer 11

SO32-

Question 12

Nitrite

Answer 12

No2-

Question 13

How does phosphorus exist

Answer 13

P4

Question 14

Avogadros constant

Answer 14

6.02x10^23/mol
1 mol= the amount of substance that contains 6.02x10^23 particles
12g of carbon 12 has 6.02x10^23 particles

Question 15

Molar mass

Answer 15

Gmol^-1

Question 16

Molecular formula

Answer 16

The actual number of atoms of each element in a molecule

Question 17

Empirical formula

Answer 17

The simplest whole number ratio of atoms of each element in a compound

Question 18

Relative molecular mass

Answer 18

For simple molecules compares the mass of a molecule the mass of an atom of carbon 12

Question 19

Relative formula mass

Answer 19

Mass of empirical unit compares the mass of a formula unit with the mass of an atom of carbon 12

Question 20

Assumptions one finding formula of hydrated salts

Answer 20

All water has been lost and no further decomposition

Question 21

Volume of one mole of gas molecules

Answer 21

24dm^3

Question 22

Moles gas vol

Answer 22

Vol=mol x 24

Question 23

Ideal gas equation assumptions

Answer 23

Random motion elastic collisions negligible size no intermolecular forces

Question 24

Ideal gas equation

Answer 24

pV=nRT
P=pressure Pa
V=vol m^3
N=mols 
R=constant 8.314
T=temp in K

Question 25

Atom economy

Answer 25

A measure of how well atoms have been utilised
Hi atom economy produce large proportion of desired product and are important for sustainability
Atom economy=sum of molar mass of desired product/total mass of products x100