Chemistry

Question 1

Relative Atomic Mass

Answer 1

The weighted mean mass of an atom of an element compared to 1/12th the mean mass of an atom of an element on carbon-12

Question 2

Relative Isotopic Mass

Answer 2

The mean mass of an atom of an element relative to 1/12th the mean mass of an atom of carbon-12

Question 3

Charge of NO3

Answer 3

-1

Question 4

Charge of NO2

Answer 4

-2

Question 5

Empirical Formula

Answer 5

Simplest whole number ratio

Question 6

pV=nRT units

Answer 6

p=Pascals
V=M^3
n=Number of moles
T=Kelvin

Question 7

Percentage yield formula

Answer 7

Experimental mass / theoretical mass times by 100

Question 8

Strong Acid

Answer 8

An acid that fully dissociated in an aqueous solution

Question 9

Standard Solution method

Answer 9

Weigh by weigh by difference
Dissolve the solid using less distilled water then needed and stir with a glass rod
Transfer to the volumetric flask and add washings
Make up to the 250cm^3 mark so that the bottom of the miniscus is on the line
Inverted multiple times so that the concentration is equal throughout.

Question 10

Shells

Answer 10

A group of atomic orbitals that have the same principal quantum number

Question 11

Atomic Orbitals

Answer 11

A region of an atom that can hold up to 2 electrons with opposite spins

Question 12

Chlorine in cold alkali

Answer 12

Occurs at 15 degrees
Cl2 + 2NaOH gives you NaCl + NaClO + H(2)0

Question 13

Chlorine with water (reactions that occur in the swimming pool)

Answer 13

Cl(2) + H(2)o gives HCl + HClO

Question 14

What kills bacteria in the water

Answer 14

Chloric acid (HCLO) and (ClO-) - the product formed when chloric acid dissociates

Question 15

Chlorine with sunlight

Answer 15

2Cl(2) + 2H(2)O gives 4HCl + O(2)

Question 16

Acid

Answer 16

Proton Donor

Question 17

Base

Answer 17

Proton Acceptor

Question 18

Alkali

Answer 18

A soluble base that dissolves in an aqueous solution to release OH- ions

Question 19

Colours of Chlorine, Bromine and Iodine in silver nitrate

Answer 19

Chlorine = White
Bromine = Cream
Iodine = Yellow

Question 20

What happens to halides in dilute NH3

Answer 20

Chloride dissolves

Question 21

What happens to halides in concentrated NH3

Answer 21

Bromine dissolves

Question 22

Colours of Halogens in aqueous solution

Answer 22

Chlorine = Pale-green
Bromine = Orange
Iodine = Brown

Question 23

What is the halogen that changes colour in cyclohexane

Answer 23

Iodine to violet

Question 24

Test for carbonate ions

Answer 24

Add dilute acid, effervescence

Question 25

Test for Sulfate ions

Answer 25

Barium nitrate, white precipitate forms

Question 26

Solid Barium Nitride with water forming an alkaline solution

Answer 26

Ba3N2 + 3H(2)O gives 3Ba(OH)2 + 2NH3. Forms barium hydroxide

Question 27

Explain the anomalous properties in water

Answer 27

Solid is less dense then the liquid state as in the solid lattice, hydrogen bonding hold molecules apart. H(2)O have relative high boiling points compared to other simple covalent molecules due to the incredibly strong hydrogen bonding H(2)O have a high surface tension

Question 28

Dative Covalent Bond

Answer 28

A covalent bond where the bonding pair of electrons have been donated by 1 atom only

Question 29

Covalent bond

Answer 29

Electrostatic attraction between the bonding pairs of electrons and the positive nucleus

Question 30

Covalent structure of NO3-

Answer 30

Uses a triangle on the O- atom

Question 31

Explain what is meant by an ionic lattice

Answer 31

Repeating pattern of oppositely charged ions

Question 32

Down the group

Answer 32

Atomic radius increases Shielding increases These outweigh the increase in nuclear charge Therefore the nuclear force of attraction on the highest energy electron increases

Question 33

Across the period

Answer 33

Atomic radius decreases Shielding stays the same Nuclear charge increases Force of attraction on the highest energy electron increases

Question 34

Formula of Nitric Acid

Answer 34

HNO3

Question 35

First ionisation energy --------- across a period and ------- down a group

Answer 35

Increases across a period and decreases down the group

Question 36

Which type of ionisation energy graph looks weird

Answer 36

First ionisation energy

Question 37

Explain the decrease in successive ionisation energy from group 2 to group 3

Answer 37

p-orbital has a higher energy than s-orbital. Therefore requires less additional energy to remove an electron

Question 38

Explain the decrease of successive ionisation energy from group 5 to group 6

Answer 38

Group 6 causes a pair of electron to form which repels. Therefore less energy required to remove the highest energy electron