Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

science exam study > freesciencelesosns chemistry > Flashcards

freesciencelesosns chemistry Flashcards

1
Q

What is ionising

A

when a acid molecule splits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a strong acid

A

an acid that fully ionises in an aqueous solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Three examples of strong acids

A

hydrochloric acid
Sulfuric acid
nitric acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is a weak acid

A

Weak acids partially ionise in aqueous solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

three examples of weak acids

A

Carbonic acid
ethanoic acid
citric acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does the pH scale tell us about the concentration of hydrogen ions in acids

A

As the pH scale decreases by one unit, the concentration of hydrogen ions increases by ten times

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a compound

A

compounds contain two or more different elements chemical combined in a fixed proportion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How to separate a compound back into its elements

A

you need to use a chemical reaction to do this

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define mixture

A

a mixture has different elements/compounds not chemical combined together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How to separate a mixture

A 
use a physical technique, rather than a chemical reaction
Filtration 
distilation
Crystallisation 
chromatography
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is a molecule

A

a molecule has any elements chemicaly joined

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What happens when we react an acid with a base or an alkali

A

we make a salt and water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens when we react an acid with a metal carbonate

A

they make a salt, water and carbon dioxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a polymer made of

A

thousands of small identical molecules joining together (called monomers)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the two types of polymers

A

Addition polymers and condensation polymers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how to name polymer

A

The word poly followed by the name of the monomer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what does the word poly mean

A

many

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are addition polymers formed form

A

they are formed from alkenes

All of the atoms in the monomer end up in the polymer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How are condensation polymers made

A

they are made from monomers, but they are not alkenes

When these monomers react, we lose small molecules such as water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How does the reactivity series work in displacement

A

a more reactive element will push out a less reactive element from its compound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is reduction

A

The loss of oxygen and the gain of electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is oxidation

A

The gain of oxygen and the loss of electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

OILRIG

A

Oxidation is loss

reduction is gain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Can solid ionic compound conduct electricity

A

no, the ions are locked in place and are not free to move

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What happens when an ionic compound is melted or dissolved in water

A

The forces of attraction are broken and the ions are free to move
these liquids and solutions can now conduct electricity
Scientists call these liquids or solutions electrolytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Describe cathode and anode

A

cathode covered with electrons (attracts positives)

Anode lack of electrons (attracts negatives0

27
Q

name an important use for ammonia

A

To make nitrogen based fertilisers for farming

28
Q

What are the raw materials for the Harber process

A

nitrogen and hydrogen
N2(g) + 3H2(g) = 2NH3(g)

Reversible reaction

29
Q

define catalyst

A

catalysts increase the rate of reaction but are not used up during the reaction

This saves money because it makes reactions faster without needing temperature increase

You can reuse catalysts

30
Q

how to change the direction of reversible reactions

A

By changing the conditions

31
Q

giant covalent molecules properties

A

Giant covalent molecules are always solids at room temperature
they have millions of strong covalent bonds
They always have high melting and boiling points

32
Q

How is diamond formed

A

it is formed from carbon
each carbon atom is connected to four covalent bonds to other carbons
It can’t conduct because there are no free electrons

33
Q

Silicon dioxide properties

A

high melting and boiling point
covalent bond between oxygen and silicon
A huge number of strong covalent bonds must be broken and this takes a great deal of energy

34
Q

Reactivity series

A 
potasisum
Sodium
lithium
calcium
Magnesium 
aluminium

carbon

Zinc
iron
copper

35
Q

how is aluminium extracted

A

Aluminium is extracted from the compound aluminium oxide by electrolysis

36
Q

alumium oxide melting point

A

2000 oC

37
Q

what does cryolite do

A

Cryolite lowers melting point

38
Q

electrolysis reaction of aluminium oxide

A

Al3+ 3e- —> Al

Reduction

39
Q

Why is electrolysis expensive

A

melting the compounds requires a great deal of energy

A lot of energy is required to produce the electric current

40
Q

what atoms are Nobel gasses

A

Group zero

41
Q

properties of Nobel gas

A

They are unreactive because they have full outer shells
Their boiling points are lower than rtp
their boiling points increases as the relative atomic mass increases

42
Q

define the term proton number

A

number of proton

protons in the nucleus (of an atom)

43
Q

Explain why the chemical properties of Mg 24/12 and Mg 26/12 (isotopes) are the same

A

same number of electrons

(same number) of electrons in the outer shell

44
Q

suggest the differences in the melting point and boiling point with an impure substance compared to a pure substance

A

melting point decreases

boiling point increases

45
Q

State three properties of transition elements

A

It has variable oxidation states
they act as catalysts
They form coloured compounds

46
Q

State the full name of the compound of copper that can test for water

A

anhydrous copper (II) sulfate

it turns from white to blue in the presence of water

47
Q

Define the term acid

A

proton donor

48
Q

conditions to keep the same during practicals

A

Volume, concentration, temperature, mass, size

49
Q

How to obtain pure crystals

A

evaporation
the starting of crystallisation
drying the crystals

50
Q

What is meant by the term precipitate

A

a solid which forms when two solutions are mixed / reacted / added

51
Q

What is the general formula of alkenes

A

Cn H2n

52
Q

How are tiny insoluble particles removed from water during the purification process?

A

chemicals are added to the impure water which cause tiny insoluble particles to clump together and settle out

53
Q

What can be used to identify whether a sample of water is hard or soft?

A

Soap solution is added drop by drop and the water sample is shaken. The more drops it takes to get a stable lather (bubbles) the harder the water is.

54
Q

What ions cause hardness in water?

A

hardness in water is caused by calcium and magnesium ions.

55
Q

What dissolved compound is responsible for causing temporary hardness in water?

A

Calcium hydrogencarbonate causes temporary hardness in water.

56
Q

Slag forms as a waste product in the production of iron. What is slag?

A

Slag is calcium silicate

57
Q

What is the name of the process that uses plants to extract metals from an ore?

A

Phytoextraction is the process that uses plants to extract metals from an ore.

58
Q

What is a disadvantage of bioleaching?

A

The bacteria used in bioleaching produce sulfuric acid as a by-product.

59
Q

What colour change could occur when hydrochloric acid is added to an alkaline solution containing universal indicator?

A

When hydrochloric acid is added to an alkaline solution containing universal indicator, the colour could change from purple to red.

60
Q

What is the general equation for the reaction of a metal with an acid?

A

The general equation for the reaction of a metal with an acid is: metal + acid → salt + hydrogen

61
Q

What products are formed when hydrochloric acid reacts with copper carbonate?

A

The products of the reaction between hydrochloric acid and copper carbonate are copper chloride, water and carbon dioxide.

62
Q

Natural rainwater has a pH of 5. The most acidic rain ever recorded in Britain was 1000 times more acidic than natural rainwater. What was its pH? - Higher

A

The pH is 2

63
Q

What mass of iron will be made when 16g of Fe2O3 reacts in the thermite reaction Fe2O3 + 2Al → 2Fe + Al2O3?

A

The number of moles of iron oxide reacting is given by 16 / 160 = 0.1. The balanced equation shows there will be 0.2 moles of Fe made, so the mass is 0.2 x 56 = 11.2 g. You needed to divide the starting mass by the Mr of iron oxide.

science exam study (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions