Chapter 1

Question 1

relative atomic mass

Answer 1

Ar
no units
compare mass of 1 atom of element, relative to 1/12th of mass of 1 atom of carbon-12

Question 2

relative molecular mass

Answer 2

Mr
daltons (Da)
sum of Ar of all atoms in compound

Question 3

Avogadro constant

Answer 3

6. 02x10^23 mol-1

no. molecules/atoms/ions in 1 mole

Question 4

1 mole

Answer 4

amount of substance that contains as many entities as 12g of carbon-12
contains 6.02x10^23 atoms

Question 5

no. moles =

Answer 5

mass substance/mass of 1 mole(molar mass)

mol=g/MW

Question 6

empirical formula

Answer 6

simplest whole number ratio of elements in compound
e.g. C6H12O6 = CH20

calculate moles of each element (mass divided by molar mass)
ratio of moles
whole numbers

Question 7

how to get from empirical to molecular formula

Answer 7

need to know relative molecular mass (Mr)

count Mr of empirical formula then actual Mr/empirical Mr gives factor by which times formula

Question 8

Molar=

1 Molar

Answer 8

mol/V

1 mol/L

Question 9

concentration

Answer 9

amount of solute per unit volume

Question 10

dynamic equilibrium

Answer 10

rate of forward and backward reaction is the same so no net change in conc. of reactants and products

Question 11

homogenous equilibria

Answer 11

reactant and products in the same state

Question 12

equilibrium constant (Kc)

Answer 12

relates conc. of reactants and products
large value = forward reaction, product conc. high
low value = backward reaction, low product conc.

Question 13

Le Chatelier’s principle

Answer 13

when an equilibrium reaction is subject to change in conditions, composition of mixture adjusts to counteract change

Question 14

catalysts effect

Answer 14

doesn’t change Kc, just gets faster, position of equilibrium unchanged, just reaches equilibrium quicker