Brainscape's Knowledge GenomeTM

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


See full index

CHEMISTRY ADDITIONAL > 2a > Flashcards

2a Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Chemistry flashcards Periodic Table flashcards Chemistry 101 flashcards Organic Chemistry 101 flashcards
1
Q

What is the mass number?

A

The total number of protons and neutron

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

What is the atomic number?

A

The number of protons

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

What are the masses of protons, neutrons and electrons?

A 
Protons= 1
Neutrons= 1
Electron = very small
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a compound?

A

Atoms of two or more elements chemically combined together

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

Define isotope

A

Different atomic forms of the same element, which have the same number of protons but a different number of neutrons

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

What happens in ionic bonding?

A

Atoms lose or gain electrons to form charged particles (ions) which are then strongly attracted to one another

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

What kind of structure do Ionic compounds always have?

A

Regular lattice

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

What do ionic compounds always have in them?

A

Giant ionic lattices

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

In ionic compounds how strong are the electrostatic forces of electron between the oppositely charged ions, in all directions

A

Very strong

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

Give an example of a giant ionic lattice

A

Salt (sodium chloride)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Name 3 properties of ionic compounds

A

High melting points, high boiling points due to strong attraction between the ions & dissolve easily in water

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

What is covalent bonding?

A

When atoms share electrons to complete their outer shell

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

What are the two kinds of covalent substances?

A

Simple molecular substances, giant covalent structures (macromolecules)

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

Describe the properties of simple molecular substances

A

Atoms form very strong covalent bonds to form small molecules of several atoms. Forces of attraction between molecules is weak. low bp &mp. don’t conduct electricity

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

Describe the properties of giant covalent structures

A

No charged ions, atoms bonded to each other by strong covalent bonds. high bp & mp. Don’t conduct electricity

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

Give three examples of simple molecular substances

A

Chlorine, Oxygen, Water

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

Give three examples of giant covalent structures

A

Diamond, Graphite, Silicon Dioxide (Silica)

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

What is the hardest natural substance?

A

Diamond

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

What is each grain of sand made up of?

A

One giant structure of silicon and oxygen

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

Which non-metal can conduct heat and electricity well and why?

A

Graphite- three covalent bonds, layers free to slide over each other, weak intermolecular forces between layers. Each carbon atom has one delocalised electron, conduct heat and electricity

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

What are metal properties due to?

A

The sea of free electrons

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

Name 3 properties of metals due to their electrons

A

Good conductors of heat and electricity because free to move, hold the atoms together in a regular structure due to strong electrostatic attraction between positive metal ions and negative electrons. Allow layers of atoms to slide over each other, allowing metals to be bent and shaped.

23
Q

What are harder alloys or pure metals and why?

A

Alloys, have different sized atoms so more difficult for them to slide over each other

24
Q

Give an example of a smart material

A

Nitinol

25
Q

Roughly how many atoms do nanoparticles contain?

A

A few hundred atoms

26
Q

What are fullerenes?

A

Molecules of carbon, shaped like hollow balls or closed tubes. Different fullerenes contain different numbers of carbon atoms.

27
Q

Fullerenes can be joined together to form…

A

Nanotubes

28
Q

Name 3 useful aspects of nano science

A

Huge surface area to volume ratio for catalysts, stronger and lighter building materials, conduct electricity so could be used for computer chips

29
Q

What determines the properties of plastics?

A

Forces between molecules

30
Q

If there are weak intermolecular forces in a polymer what can it do and what type of polymer is it?

A

Free to slide over each other and creates thermo-softening polymers

31
Q

Describe thermo-softening polymers

A

Don’t have cross-linking between chains, forces between chains are easy to overcome, easy to melt the plastic.

32
Q

If there are strong intermolecular forces in a polymer what does it have and what type of polymer is it?

A

Crosslinks that hold the chains firmly together and creates thermosetting polymers

33
Q

Describe thermosetting polymers

A

Have cross-links between chains, solid structure, doesn’t soften when heated, strong, hard rigid

34
Q

What two things will affect the properties of a polymer?

A

Starting materials and reaction conditions

35
Q

What hold the atoms together in long chains in polymers?

A

Strong covalent bonds

36
Q

How is Low density (LD) polythene made and what is it used for?

A

Made by heating ethene to about 200c under high pressure. Its flexible and is used for bags and bottles

37
Q

How is High density (HD) polythene made and what is it used for?

A

Made at lower temperature and pressure (with a catalyst). It is more rigid and is used for water tanks and drainpipes

38
Q

What is relative atomic mass?

A

Mass number

39
Q

What is the relative formula mass?

A

All relative atomic masses added together

40
Q

What is one mole of a substance equal to?

A

The relative formula mass in grams

41
Q

What is the equation for working out the number of moles in a substance?

A

Number of moles = Mass in g (of element or compound / Relative formula mass

42
Q

What is the equation to calculate the percentage mass of an element in a compound?

A

Relative atomic mass x No. of atoms (of that element) / RFM (of whole compound) x100

43
Q

How do you work out the empirical formula?

A

list all the elements in the compound with their experimental masses or percentages, divide each mass by the relative atomic mass for that element, make numbers nicer by multiplying and/or dividing, ratio in simplest form is the empirical formula.

44
Q

How do you calculate masses in reactions?

A

Write out the balanced equation, work out the RFM for the bits you need, apply rule divide to get one, then multiply to get all

45
Q

What is the formula to calculate the percentage yield?

A

Percentage yield= actual yield (grams) / predicted yield (grams) x100

46
Q

Give three possible explanations for why there is never an 100% yield

A

The reaction could be reversible, when filtering nearly always lose a bit of the solid or liquid when its separated from the reaction mixture, can be other unexpected reactions which use up the reactants

47
Q

How can artificial colours be separated?

A

Paper chromatography

48
Q

How does paper chromatography work?

A

Put spots of coloured solution on a pencil baseline on filter paper, roll up sheet and put it in beaker with solvent. Solvent seeps up paper taking dyes with it.

49
Q

Name three advantages to using instrumental methods to identify elements and compounds

A

Very sensitive (can detect even the tiniest amounts of substances), very fast ad tests can be automated, very accurate

50
Q

What can be used to identify substances?

A

Gas chromatography

51
Q

Explain the process of gas chromatography

A

A gas is used to carry substance through a column packed with solid material. The substances travel through the tube at different speeds so their separated. The time they take to reach the detector is the retention time, used to identify the substances. Record draws a gas chromatograph.

52
Q

On a gas chromatograph, what does the number of peaks and the position of the peaks show?

A

The no. of peaks shows the no. of different compounds in the sample, position of peaks shows the retention time for each substance

53
Q

What is retention time?

A

Time taken for a compound to reach the detector in gas chromatography

54
Q

What can a gas chromatography column be linked up to and what can it do?

A

Can be linked to a mass spectrometer, can identify the substances more accurately.

CHEMISTRY ADDITIONAL (2 decks)

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