Module 2 Chapter 2

Question 1

Isotopes

Answer 1

Atoms of the same element (same number of protons and electrons) with different numbers of neutrons.

Question 2

Relative isotopic mass

Answer 2

Mass (of an isotope) compared to 1/12th of the mass of carbon-12

Question 3

Relative atomic mass

Answer 3

Weighted mean mass of an element compared with 1/12th of the mass of carbon-12

Question 4

Mass Spectrometry: Ionisation

Answer 4

Gaseous particles are injected into the spectrometer and hit by a high energy beam of electrons. This causes them to become positive ions.

x_(g) + e^- —> x^+ + 2e^-

Question 5

Mass Spectrometry: Acceleration

Answer 5

Particles are then accelerated by a magnetic field.

Question 6

Mass spectrometry: Drift Region

Answer 6

Through the drift region, particles travel at different speeds (as heavier ions move more slowly), so separate and hit the ion detector at different times.

The ion detector then detects the ions when they arrive, and feeds a signal into a computer, producing relative abundance of ions against the mass/charge ratio (mass/1+)

Question 7

Relative Atomic Mass Equation

Answer 7

(%isotopic mass+%isotopic mass)/100

Question 8

Do you always divide by 100 when finding RAM?

Answer 8

Not when multipliers don’t sum 100%

Question 9

Ammonium ion

Answer 9

NH4^+

Question 10

Hydroxide ion

Answer 10

OH^-

Question 11

Nitrate

Answer 11

NO3^-

Question 12

Nitrite

Answer 12

NO2^-

Question 13

Hydrogencarbonate

Answer 13

HCO3^-

Question 14

Permaganate/Maganate(VII)

Answer 14

MnO4^-

Question 15

Carbonate

Answer 15

CO3^2-

Question 16

Sulphate

Answer 16

SO4^2-

Question 17

Sulphite

Answer 17

SO3^2-

Question 18

Dichromate(VI)

Answer 18

Cr2O7^2-

Question 19

Phosphate

Answer 19

PO4^3-

Question 20

Silver

Answer 20

Ag+

Question 21

Zinc

Answer 21

Zn2+