Brainscape's Knowledge GenomeTM

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


See full index

OCR Chemistry AS 2016 > Module 2: Definitions > Flashcards

Module 2: Definitions Flashcards

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

Define relative formula mass.

A

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

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

Define relative atomic mass.

A

(Ar)

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

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

Define relative isotopic mass.

A

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

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

Define relative molecular mass.

A

(Mr)

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

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

What is an ionic bond?

A

Electrostatic force of attraction between cations and anions.

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

What is a metallic bond?

A

Electrostatic attraction between cations (positive metal ions) and delocalised electrons.

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

What is a covalent bond?

A

Strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms.

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

What are isotopes?

A

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

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

What are IMF’s?

A

Intermolecular force.

An attractive force between molecules. Intermolecular forces can be London forces, permanent dipole-dipole interactions or hydrogen bonding.

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

What is a hydrogen bond?

A

A strong dipole-dipole attraction between an electron-deficient hydrogen atom of -NH, -OH or HF on one molecule and a lone pair of electrons on a highly electronegative atom containing N, O or F on a different molecule.

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

What is the empirical formula?

A

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

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

What is the molecular formula?

A

A formula that shows the number and type of atoms of each element present in a molecule.

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

Define stoichiometry.

A

The ratio of the amount, in moles, of each substance in a chemical equation (essentially the ratio of the balancing numbers).

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

Define anhydrous.

A

Containing no water molecules.

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

Define hydrated.

A

A crystalline compound containing water molecules.

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

Define water of crystallisation.

A

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

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

Define dative covalent.

A

A shared pair of electrons in which the bonding pair has been provided by one of the bonding atoms only; also called a coordinate bond.

18
Q

What is Avogadro’s constant?

A

(Na)

The number of atoms per mile of the carbon-12 isotope.

6.02x10^23 mol^-1

19
Q

Define molar mass.

A

(M)

The mass per mole of a substance, in units of gmol^-1.

20
Q

What is molar gas volume?

A

(Vm)

The volume per mole of gas molecules at a stated temperature and pressure.

21
Q

What is a mole?

A

The amount of any substance containing as many elementary particles as there are carbon atoms in exactly 12g of the carbon-12 isotope, that is, 6.02x10^23 particles.

22
Q

What is percentage yield?

A

% yield =
actual amount of product (mol)
__________________________________

theoretical amount of product (mol)

X100

23
Q

Define atom economy.

A

Sum of molar masses of desired products

/ divided by

Sum of molar masses of all products

Å ~ 100

24
Q

What is sustainability?

A

Carrying out chemical processes without depleting the Earth’s natural resources or damaging the environment.

25
Q

What is an acid?

A

A species that releases H+ ions in aqueous solution.

26
Q

What is a base?

A

A compound that neutralises an acid to form a salt.

27
Q

What is an alkali?

A

A type of base that dissolves in water to release hydroxide ions, OH- (aq).

28
Q

What is a weak acid?

A

An acid that dissociates only partially in solution.

29
Q

What is a strong acid?

A

An acid that dissociates completely in solution.

30
Q

What is a salt?

A

The product of a reaction in which the H+ ions from the acid are replaced by metal or ammonium ions.

31
Q

Define oxidation.

A

Loss of electrons or an increase in oxidation number.

32
Q

Define reduction.

A

Gain of electrons or decrease in oxidation number.

33
Q

What is a redox reaction?

A

A reaction involving both reduction and oxidation.

34
Q

What is an oxidising agent?

A

A reagent that oxidises (takes electrons from) another species.

35
Q

What is a reducing agent?

A

A reagent that reduces (adds electrons to) another species.

36
Q

What is a shell (electron shell)?

A

A group of atomic orbitals with the same principal quantum number n. Also known as a main energy level.

37
Q

What is a subshell?

A

A group of orbitals of the same type within a shell.

38
Q

What is an orbital?

A

A region of space around the nucleus that can hold up to two electrons as long as their spins are paired (opposite spins).

39
Q

Define electronegativity.

A

A measure of the attraction of a bonded atom for the pair of electrons in a covalent bond.

40
Q

What are polar molecules?

A

A molecule with an overall dipole, having taken into account any dipoles across bonds and the shape of the molecule.

OCR Chemistry AS 2016 (2 decks)

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