1.3 formulae, equations, moles Flashcards Preview

Chemistry AS (2015) > 1.3 formulae, equations, moles > Flashcards

Flashcards in 1.3 formulae, equations, moles Deck (18):
1

a What is an atom?

a basic unit of a chemical element, with a nucleus made of protons + neutrons and electrons orbiting in shells

2

a What is an element?

an atom with a certain number of protons

3

a What is an ion?

an atom that has lost or gained electrons

4

a What is a molecule?

a group of atoms bonded together

5

a What is a compound?

a substance made of two or more elements chemically bonded together

6

a What is an empirical formula?

the smallest whole-number ratio of elements within a compound

7

a What is a molecular formula?

the number of elements in a compound displayed as e.g. C2H4

8

a What is a structural formula?

a molecule displayed in groups e.g. CH2 = CH2

9

a What is a displayed formula?

a molecule drawn showing all bonds as lines

10

b How do you construct an ionic equation?

write out all ions + non-aqueous compounds
cross out those that are the same either side (spectator ions)

11

c What is RAM?

a weighted average of the masses of isotopes of an element relative to 1/12 of a C-12 atom

12

c What is molar mass?

the mass of one mole of a substance, measured in g/mol

13

d How can you calculate concentration? (given moles and volume)

mol/vol

14

d How can you calculate the moles? (given mass and RFM)

moles = mass/RFM

15

f How can you calculate volume? (given moles)

vol in dm3 = mol/24

16

g How do you calculate percentage yield?

actual mass/calculated mass

17

g How can you calculate atom economy?

mass of desired product/mass of all products

18

h How many atoms are in a mole?

6.023 * 10^23