C4 - Stoichiometry

Question 1

Molecular formula shows

Answer 1

the actual amount of atoms that make up a molecule i.e C6H1206 for glucose

Question 2

empirical formula shows

Answer 2

simplest ratio of atoms which make up a molecule i.e CH2O for glucose

Question 3

chemical equation shows

Answer 3

what happens in a chemical reaction using symbols or words

Question 4

why are symbol equations balanced

Answer 4

atoms aren’t created or destroyed during chemical reactions

Question 5

ionic equations show reactions involving

Answer 5

ions

Question 6

ions that play no part in ionic reactions are called

Answer 6

spectator ions

Question 7

spectator ions are ions that

Answer 7

play no part in an ionic reaction

Question 8

relative atomic mass is

Answer 8

average mass of all isotopes of an element

Question 9

what is a mole

Answer 9

an amount of substance

Question 10

why are moles used

Answer 10

because atoms are so small its inconvenient to talk about individual atoms

Question 11

1 mole of any substance is

Answer 11

6.02 x 10^23 atoms of substance

Question 12

6.02 x 10^23 is

Answer 12

avagadros constant

Question 13

sodium chloride (NaCl) has a relative formula mass of 58.5 so what is the mass of one mole

Answer 13

58.5 g

Question 14

moles =

Answer 14

mass/relative formula mass

Question 15

a solution is made when

Answer 15

a solute dissolves in a solvent

Question 16

1 dm^3

Answer 16

is 1000cm^3

Question 17

a limiting reactant is when

Answer 17

something is completely used up so the reaction stops when it does

Question 18

what is the term when more of a reactant is used than is necessary

Answer 18

excess reactant

Question 19

concentration is measured in

Answer 19

g/dm^3 or mol/dm^3

Question 20

how much is the molar volume

Answer 20

24dm^3 or 24,000cm^3

Question 21

Percentage yield of any reaction must always be

Answer 21

less than 100%