2.1 Atoms and reactions

Question 1

What is an isotope?

Answer 1

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

Question 2

What is relative isotopic mass?

Answer 2

mass of an atom of an element compared with the mass of 1/12th of an atom of carbon-12

Question 3

Formula with moles, mass, molar mass

Answer 3

moles = mass/ molar mass

Question 4

What is the name of NO3-

Answer 4

nitrate ion

Question 5

What is the name of NH4+

Answer 5

ammonium ion

Question 6

What is the name of OH-

Answer 6

hydroxide ion

Question 7

What is the name of SO4 2-

Answer 7

sulfate ion

Question 8

What is the atomic number

Answer 8

number of protons (= electrons)

Question 9

Name the 4 common acids

Answer 9

HCL - hydrochloric acid
H2SO4 - sulfuric acid
HNO3 - nitric acid
CH3COOH - ethanoic acid

Question 10

Definition of ‘amount of substance’

Answer 10

the quantity whose unit is the mole

Question 11

What does it mean if a substance is ‘anhydrous’?

Answer 11

a substance that contains no water molecules

Question 12

What are the benefits of maximizing atom economy?

Answer 12

-more sustainable - fewer raw materials used
-minimizes chemical waste
-maximizes efficiency
-less money spent on separation process

Question 13

What is the ideal gas equation?

Answer 13

pV=nRT
p - pressure (Pa)
V - volume (m3)
n - moles
R - ideal gas constant (8.314)
T - temperature (K)

Question 14

Neutralization of acids equation

Answer 14

acid + base –> salt + water

Question 15

How does neutralization make water?

Answer 15

a bade readily accepts H+ ions from the acid
e.g. OH- accept H+ to form H2O

Question 16

Describe oxidation and reduction in terms of electron transfer

Answer 16

oxidation - loss of electrons
reduction - gain of electrons

Question 17

How to calculate percentage yield?

Answer 17

actual amount (mol) / theoretical amount (mol)
x100

Question 18

What is a strong acid?

Answer 18

acids that fully dissociate - release all their H+ ions

Question 19

What is the value of avogadros constant?

Answer 19

6.02 x 10^23

Question 20

What is ‘water of crystallisation’?

Answer 20

water molecules that form an essential part of the crystalline structure of a compound

Question 21

What is a weak acid?

Answer 21

acids that partially dissociate in water - release some of its H+ ions

Question 22

What is a base? and give examples

Answer 22

bases neutralise acids
e.g. metal oxides, metal hydroxides, ammonia

Question 23

What is a hydrated substance?

Answer 23

a crystalline substance containing water

Question 24

What is a standard solution?

Answer 24

a solution of known concentrations

Question 25

What is an acid?

Answer 25

substances that release H+ ions when dissolved in water

Question 26

What is an alkali?

Answer 26

substances that release OH- ions when dissolved in water

Question 27

What are the charges of a proton, neutron and electron?

Answer 27

+1, 0, -1

Question 28

What are the relative masses of a proton, neutron and electron?

Answer 28

1.0 1.0 1/2000

Question 29

What is the definition of relative atomic mass?

Answer 29

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

Question 30

What is CO3 2-

Answer 30

carbonate ion

Question 31

What is the formula of a zinc ion?

Answer 31

Zn 2+

Question 32

What is the formula of a silver ion?

Answer 32

Ag+

Question 33

What is the definition of ‘empirical formula’?

Answer 33

the simplest whole number ratio of atoms of each element in a compound

Question 34

What is the definition of ‘molecular formula’?

Answer 34

the number and type of atoms of each element in a molecule

Question 35

How to calculate moles using concentration and volume?

Answer 35

moles = concentration x volume

Question 36

What is the formula for atom economy?

Answer 36

(mr of desired product) / (mr of all products) x 100

Question 37

What are the 3 common alkalis?

Answer 37

NaOH - sodium hydroxide KOH - potassium hydroxide NH3 - ammonia