2.1 Atoms and Reactions (completed)

Question 1

What are isotopes?

Answer 1

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

Question 2

What is relative atomic mass?

Answer 2

weighted mean mass of an atom compared to 1/12th mass of carbon-12

Question 3

What are the common molecular ions you must remember?

Answer 3

NO 3–, CO3 2–, SO4 2–, OH–, NH4+, Zn2+ and Ag+

Question 4

What is the empirical formula?

Answer 4

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

Question 5

What is the molecular formula?

Answer 5

The actual number ratio of atoms of each element present in a compound

Question 6

What is the ideal gas equation?

Answer 6

pV=nRT
p - pressure (Pa)
V - volume (m^3)
n - number of moles (mol)
R - ideal gas constant (J/mol/K)
T - temperature (K)

Question 7

What is the formula of common acids you need to know?

Answer 7

HCl, H2SO4, HNO3 and CH3COOH

Question 8

What is the formula of common alkalis you need to know?

Answer 8

NaOH, KOH and NH3

Question 9

What is a strong acid?

Answer 9

An acid that completely dissociates in water

Question 10

What is a weak acid?

Answer 10

An acid that partially dissociates in water

Question 11

Acid + Base

Answer 11

Salt + Water

Question 12

Acid + Carbonate

Answer 12

Salt + Water + Carbon dioxide

Question 13

Acid + Metal Oxide

Answer 13

Salt + Water

Question 14

Acid + Metal Oxide

Answer 14

Salt + Water

Question 15

What is the oxidation number of manganese in Manganese (IV) Oxide?

Answer 15

+4

Question 16

What is oxidation or reduction?

Answer 16

Oxidation increase in oxidation number or loss of electrons and vice versa

Question 17

What is the oxidation number of an element?

Answer 17

0

Question 18

What is the oxidation number of an ion?

Answer 18

It’s charge

Question 19

When is the oxidation number of oxygen not normal?

Answer 19

-1 in peroxides and +2 F2O

Question 20

When is the oxidation number of chlorine not normal?

Answer 20

+1 with flourine or oxygen

Question 21

When is the oxidation number of hydrogen not normal?

Answer 21

-1 in metal hydrides

Question 22

What is Avogadro’s Constant?

Answer 22

The number of atoms in one mole of a substance

Question 23

What is a mole?

Answer 23

The amount of any substance containing as many particles as there are particles in 12g of the carbon-12 isotope.

Question 24

What is the equation for the number of moles of a substance?

Answer 24

moles = mass / Mr

Question 25

What is molecular formula?

Answer 25

The number of atoms of each element in a molecule

Question 26

In hydrated salts, what is the name given to water molecules?

Answer 26

Water of crystillisation

Question 27

What is the concentration of a solute?

Answer 27

The amount of solute (in moles) dissolved in each 1dm^3 of solution

Question 28

What is the equation for finding a solution's concentration?

Answer 28

Concentration = moles / volume

Question 29

What is the ideal gas equation?

Answer 29

``` pV=nRT p - pressure (Pa) V - volume (m^3) n - number of moles (mol) R - ideal gas constant (J/mol/K) T - temperature (K) ```

Question 30

What are standard conditions?

Answer 30

298K 100kPa or 1 atm of pressure 1.0 mol dm-3

Question 31

What is percentage yield?

Answer 31

Actual yield ———————— x100 Theoretical yield

Question 32

Why is the theoretical yield so hard to achieve?

Answer 32

Reaction is incomplete. Competing side reactions giving different products. Loss of product in handling and purification. Reversible reaction.

Question 33

What is atom economy?

Answer 33

Molar mass of desired products divided by the sum of the molar masses of all products, expressed as a percentage.

Question 34

What are the benefits of a high atom economy?

Answer 34

Produce a larger proportion of desired products and few waste products. Important for sustainability, best use of natural resources.

Question 35

What is the gas and mole equation in standard conditions?

Answer 35

moles = volume / 24

Question 36

What is water of crystalisation?

Answer 36

The water used to hydrate salts; to make anydrous salts you need to heat them. e.g. CaCl2.6H2O

Question 37

What is a Standard Solution?

Answer 37

A solution with a known concentration

Question 38

What is the atomic number?

Answer 38

The number of protons in the nucleus of an atom

Question 39

What is relative isotopic mass?

Answer 39

The mass of an atom compared to 1/2th of the mass of an atom of carbon-12

Question 40

What is the relative molecular mass?

Answer 40

The weighted mean mass of a molecule compared to 1/2th of the mass of an atom of carbon-12

Question 41

What is the relative formula mass?

Answer 41

The weighted mean mass of a formula unit compared to 1/2th of the mass of an atom of carbon-12

Question 42

What state is an acid always?

Answer 42

Aqueous

Question 43

What is an alkali?

Answer 43

Soluble bases that release OH- in water

Question 44

What does low volatility mean?

Answer 44

High boiling point