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Flashcards in Module 2.1 Deck (80)
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1

Define the term isotope

Atoms of the same element with a different number of neutrons and different masses

2

Why are the reactions of isotopes the same?

Chemical reactions only involve electrons. Isotopes have the same number of electrons. Therefore, they have the same chemical reaction

3

What is the relative mass and relative charge of a proton, neutron and electron

Proton

Relative mass = 1
Relative charge = 1

Neutron

Relative mass = 1
Relative charge = 0

Neutron

Relative mass = 1/2000
Relative charge = -1

4

What never changes? The number of neutrons, the number of protons or the number of electrons?

Number of protons

5

In the diagram of an atom, where are the electrons?

In orbitals

6

In the diagram of an atom, where is the nucleus and what is inside it?

Location - Within the first outer orbital

Inside - Protons and Neutrons

7

Define relative isotopic mass

Mass of an isotope compared with 1/12th mass of an atom of carbon-12

8

Define relative atomic mass

Weight mean mass of an atom compared with 1/12th mass of an atom of carbon-12

9

How do you find the Mr of an element?

1) Multiply each relative isotopic mass by its relative isotope abundance and then add the result
2) Divide this result by the sum of the isotope abundances

10

When do we use the term relative molecular mass?

When referring to simple molecules

11

When do we use the term relative formula mass?

When we are referring to ionic or giant covalent molecules

12

List the ions formed by Group 1 - 7 elements (excluding group 4)

Group 1 = 1+
Group 2 = 2+
Group 3 = 3+

Group 5 = 3-
Group 6 = 2-
Group 7 = 1-

13

What should we do when trying to work out the formula for ionic compounds?

Balance out the charges

14

What are the names of the following ions?

NO3 ^ -
CO3 ^ 2-
SO4 ^ 2-
OH ^ -
NH4 ^ +
Zn ^ 2+
Ag ^ +

Nitrate ion
Carbonate ion
Sulfate ion
Hydroxide ion
Ammonium ion
Zinc ion
Silver ion

15

Define amount of substance

INSERT EXAM Q DEFINITION HERE

16

Given mass and Mr, what is the formula for moles?

n = m/Mr

17

Given moles and Mr, what is the formula for mass?

m = n x Mr

18

Given moles and mass, what is the formula for Mr?

Mr = m/n

19

What is the formula for Number of particles?

n x Avogadro's constant

20

Given Avogadro's constant and the number of particles, what is the formula for moles?

Np/ Avogadro's constant

21

Define empirical formula

The simplest whole number ratio of atoms of each element present in a compound

22

How do work out the empirical formula of a compound starting from its percentage composition?

1) Divide each percentage by its atomic mass
2) Divide each answer by whichever answer is the smallest
3) Find the Lowest whole number ratio

23

How do you work out the empirical formula of a compound starting from its mass composition?

1) Divide each amount of grams by its atomic mass
2) Divide each answer by whichever answer is the smallest
3) Find the Lowest whole number ratio

24

What does anhydrous mean?

Without water

25

What does hydrated mean?

Structure consists of water

26

Define water of crystallisation

Water molecules that from an essential part of the crystalline structure of a compound

27

How do you find the water of crystallisation of a compound?

1) Work out the anhydrous mass
2) Calculate the amount of anhydrous salt (in moles)
3) Calculate the amount of water (in moles)
4) Divide the the smallest number
5) Find the lowest whole number ratio

28

For a gas at RTP, what formula would you use to work out the volume in cm^3

v = n x 24000

29

For a gas at RTP, what formula would you use to work out the volume in dm^3

v = n x 24

30

Given the concentration and volume, how can you find the number of moles?

n = C x V