foundations in chemistry

Question 1

hydroxide ion

Answer 1

OH-

Question 2

nitrate ion

Answer 2

NO3-

Question 3

ammonium ion

Answer 3

NH4+

Question 4

sulfate ion

Answer 4

SO4 2-

Question 5

carbonate ion

Answer 5

CO3 2-

Question 6

structure of sodium chloride

Answer 6

giant ionic structure

Question 7

why can ionic compounds conduct electricity when molten/ dissolved in solution

Answer 7

ions are free to move around

Question 8

why do ionic compounds have a high mp

Answer 8

strong electrostatic forces
between oppositely charged ions
require lots of energy to overcome

Question 9

what is covalent bonding

Answer 9

electrostatic attraction between shared e- and nuclei of the bonded atoms

Question 10

what are dative covalent/ coordinate bonds

Answer 10

when 1 atom donated 2 e- to an atom or ion to form a bond

Question 11

eg of dative covalent bonding

Answer 11

ammonium

Question 12

generally what happens to the bond angle when a lone pair is added

Answer 12

decreases by 2.5

Question 13

BeCl2 shape and bond angle

Answer 13

2 bond pairs
0 lone pairs
linear
180

Question 14

BF3 shape and bond angle

Answer 14

3 bond pair
0 lone pair
trigonal planar
120

Question 15

CH4 shape and bond angle

Answer 15

4 lone pair
0 bond pair
tetraheldral
109.5

Question 16

PCl5 shape and bond angle

Answer 16

5 bond pairs
0 lone pairs
trigonal bipyrimidal
90
120

Question 17

SF6 shape and bond angle

Answer 17

6 bond pairs
0 lone pairs
octahedral
90

Question 18

NH3 shape and bond angle

Answer 18

3 bond pair
1 lone pair
trigonal pyramidal
107

Question 19

H20 shape and bond angle

Answer 19

2 bond pair
2 lone pair
bent
104.5

Question 20

ClF3 shape and bond angle

Answer 20

3 bond pair
2 lone pair
trigonal planar
120

Question 21

XeF4 shape and bond angle

Answer 21

4 bond pair
2 lone pair
square planar
90

Question 22

what is electronegativity

Answer 22

ability for an atom atom attract electrons towards itself in a covalent bond

Question 23

what is the most electronegative element

Answer 23

fluorine

Question 24

how does a bond become polar

Answer 24

if atoms in a covalent bond have a difference in electronegativity

a bigger diff means more polar

Question 25

are hydrocarbons classed as polar

Answer 25

no very small diff in electronegativity

Question 26

why is CO2 not polar

Answer 26

symmetrical polar bonds no overall polarity

Question 27

list intermolecular forces in order of decreasing strength

Answer 27

h bonding permenant dipole dipole London

Question 28

what are London forces/ induced dipole dipole

Answer 28

any molecule/ atom with electrons can form a dipole when near another atom/ molecule electrons in molecule/ atom can move from one end to another dipole interaction destroyed when atoms/ molecules move away

Question 29

what are permanent dipole dipole forces

Answer 29

weak electrostatic forces between molecules with a polarity

Question 30

what is a test for polar molecules

Answer 30

charged rod near a stream of a polar liquid liquid bends towards rod

Question 31

what is h bonding

Answer 31

when hydrogen forms a bond w the lone pair on N/O/F (3 most electronegative elements)

Question 32

simple molecular eg

Answer 32

NH3 H2O

Question 33

giant ionic eg

Answer 33

NaCl CaO MgBr2

Question 34

is ice or water more dense

Answer 34

water

Question 35

what are acids

Answer 35

proton donors

Question 36

what are bases

Answer 36

proton acceptors

Question 37

what is an alkali

Answer 37

soluble base

Question 38

weak acid eg

Answer 38

ethanoic

Question 39

strong acid eg

Answer 39

hydrochloric nitric sulfuric

Question 40

weak base eg

Answer 40

ammonia

Question 41

strong base eg

Answer 41

sodium hydroxide potassium hydroxide

Question 42

what are polyprotic acids

Answer 42

donate more than one proton

Question 43

acid + base =

Answer 43

salt + water

Question 44

NH3 + H2O =

Answer 44

NH4+ + OH-

Question 45

metal + acid =

Answer 45

salt + hydrogen

Question 46

metal oxide + acid =

Answer 46

salt + water

Question 47

metal hydroxide + acid =

Answer 47

salt + water

Question 48

metal carbonate + acid =

Answer 48

salt + water + carbon dioxide

Question 49

indicators eg

Answer 49

phenolphthalein acid- colourless alkali- pink methyl orange acid- red alkali- yellow

Question 50

method for making a standard solution

Answer 50

1. weigh solid precisely w a balance and weighing boat 2. transfer to beaker, wash any solid left into beaker w deionised water 3. fully dissolve solid w deionised water, stir 4. transfer solution to volumetric flask using a funnel, rinse beaker and glass rod w deionised water 5. deionised water to fill volumetric flask till graduation line, use pipette 6. invert flask to thoroughly mix solution

Question 51

oxidation number of aluminium

Answer 51

+3

Question 52

systemic name of ClO2-

Answer 52

chlorate (III)

Question 53

exceptions to Aufbau principle

Answer 53

Cr 3d5 4s1 Cu 3d10 4s1

Question 54

equation w 24dm3

Answer 54

24dm3 = volume dm3 / moles

Question 55

relative isotopic mass definition

Answer 55

mass compared with 1/12th mass of carbon-12

Question 56

relative atomic mass definition

Answer 56

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

Question 57

method to find water of crystallisation

Answer 57

heat hydrated salt removes water of crystallisation leaves anhydrous salt

Question 58

idea gas equation units for pressure

Answer 58

Pa

Question 59

idea gas equation units for volume

Answer 59

m^3

Question 60

idea gas equation units for temperature

Answer 60

K

Question 61

how to convert ºC to K

Answer 61

+ 273

Question 62

how to convert m^3 to dm^3 and dm^3 to cm^3

Answer 62

x 1000

Question 63

what is the oxidation number of O in peroxides

Answer 63

-1

Question 64

what is the oxidation number of H in metal hydrides

Answer 64

-1

Question 65

how to count sigma and pi bonds

Answer 65

a single bond has 1 sigma bond a double bond has 1 sigma and 1 pi