Module 2 Flashcards Preview

Chemistry OCR 2015 Onwards > Module 2 > Flashcards

Flashcards in Module 2 Deck (31)
Loading flashcards...
1

Proton Number

The number of protons in the nucleus of an atom

2

relative atomic mass

The weighted mean mass of an atom of an element compared with
one-twelfth of the mass of an atom of carbon-12.

3

relative formula mass

The weighted mean mass of the formula unit of a compound compared
with one-twelfth of the mass of an atom of carbon-12.

4

relative isotopic mass

The mass of an atom of an isotope compared with one-twelfth of the
mass of an atom of carbon-12.

5

relative molecular mass

The weighted mean mass of a molecule of a compound compared
with one-twelfth of the mass of an atom of carbon-12.

6

isotopes

Atoms of the same element with different numbers of neutrons and different masses

7

molar mass

The mass per mole of a substance

8

mole

The amount of any substance containing as many elementary particles as there are carbon
atoms in exactly 12 g of the carbon-12 isotope, that is, 6.02 × 1023 particles.

9

anhydrous

Containing no water molecules

10

anion

A negatively charged ion with more electrons than protons.

11

cation

A positively charged ion with fewer electrons than protons.

12


concentration

The amount of solute, in moles, dissolved in 1dm3
(1000 cm3
) of solution

13

empirical formula

a The formula that shows the simplest whole-number ratio of atoms of each
element present in a compound.

14

hydrated

A crystalline compound containing water molecules

15


molecular ion

The positive ion formed in mass spectrometry when a molecule loses an electron

16

water of crystallisation

Water molecules that are bonded into a crystalline structure of a
compound

17

Equation to work out moles of a solid

Moles = mass/Mr

18

Equation to work out moles of a solution

moles = MV/1000

19

Equation to work out moles of a gas (in standard conditions)

moles = volume (dm3)/24

20

Ideal Gas Equation

PV=nRT
P = pressure in Pa
V = volume in m3
n = no. of moles
R = gas constant (8.31)
T = temperature in K

21

What is 25oc in Kelvin?

25+273 = 298K

22

Define strong acid

Completely dissociates in aqueous solution

23

Define weak acid

Partially dissociates in aqueous solution

24

Define Bronsted-Lowry acid

Proton donor

25

Define base

Proton acceptor

26

Define salt

When the proton of an acid is replaced by a metal ion

27

Define oxidation

Loss of electrons

28

Define reduction

Gain of electrons

29

What is the oxidation number of any element

0

30

What is the oxidation number of oxygen generally (with the exception of in peroxide)

-2

31

What is the oxidation number of sulphur in CaSO4

+6