Brainscape's Knowledge GenomeTM

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


See full index

CHEMISTRY > GROUP 7 > Flashcards

GROUP 7 Flashcards

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

What is the trend in the boiling point down group 7? why? (4)

A

Increases down the group
size of atoms increases
increase in number of electron so
stronger van der waals forces of attraction between molecules require more energy to overcome

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

What is the trend in electronegativity down group 7? Why? (5)

A

Decreases
increased atomic radius
more shielding
outer e- further away from nucleus
more difficult yo attract electron density in a covalent bond

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

state and explain trend in oxidising ability in group 7

A

going down G7 halogens become weaker oxidising agents.
Larger radius
Weaker attraction between nucleus and outer e-

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

Describe what you would see if you combined the following reagents and write stoichiometric and ionic equations for any reactions that take place

  1. Br2 (aq) with NaF (aq)
  2. Cl2 (aq) with NaBr (aq)
  3. Br2 (aq) with NaI (aq)
A
  1. No reaction occurs, Bromine can’t displace fluoride
  2. An orange- brown solution forms
    Cl2(aq) + 2NaBr(aq) –> 2NaCl(aq) + Br2(aq)

Cl2(aq) + 2Br-(aq) –> 2Cl-(aq) + Br2(aq)

  1. Orange solution turns brown
    Br2(aq) + 2NaI(aq) –> 2NaBr(aq) + I2(aq)

Br2(aq) + 2I-(aq) –> 2Br-(aq) +I2(aq)

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

State and explain the trend in reducing ability of the halide ions

A

Reducing strength increases down group
ions radius increases
Weaker attraction between outer e- and nucleus

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

Identify 2 solid sodium halides that can’t reduce concentrated sulphuric acid. write simplest ionic equations for a reaction occurring with just on for a reaction occurring with just one of theses halides and give oberservations

A

H+ + F- –> HF
Ob: misty fumes of HF gas
H+ + Cl- –> HCl
Ob: misty fumes of HCl gas

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

state the observation you would make if either of NaCl or NaF was reacted with concentrated sulphuric acids

A

steamy white fumes

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

Name the products formed when solid NaBr reacts with concentrated H2SO4 and state the observations you would make upon their function

A

Steamy fumes of HBr
brown fumes of Br2
colourless fum of SO2 gas
colourless solution of NAHSO4

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

Write redox equations for the formation of Br with H2SO4

A

2Br –> Br2 + 2e-
H2O4 + SH+ + 2e- –> SO2 + 2H2O
H2SO4 + 2H+ + 2Br- —> SO2 + 2H2O + Br2

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

Give a common use of Sodium hypochlorite (NaClO)

A

used as disinfectant as it kills bacteria

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

Write and equation for the reaction between Chlorine and cold dilute sodium hydroxide

A

Cl2(g) + 2NaOh(aq) —-> NaCl(aq) + NaClO(aq) + H2O(l)

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

Even though chlorine is toxic , why do we add it to swimming pools? (2)

A

adding chlorine to swimming pools kills bacteria.
health benefits of adding very small amount if Cl to water outweigh the risks

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

write equation for the reaction between H2O and Cl in the presence of direct sunlight

A

2Cl2(g)+ 2H2O (l) (EQUALIBRIUM SIGN) 4HCl (aq) + O2(g)

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

What does disproportination reaction mean?

A

reaction in which one reactant species is simultaneously oxidised and reduced

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

write the equation for the reaction between water and chlorine to form 2 chlorine- containing products

A

Cl2(g) + H2O(l) (EQUILIBRIUM ARROW) HCL(aq) + HCLO(aq)

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

test for carbonate ions

A

Add H2SO4
effeservence
Co2 produced

17
Q

<write a half equation for the formation of Iodine from Iodide ions

A

2I- —-> I2 + 2e-

18
Q

Test for hydroxide ions

A

MgCl2
White ppt
Mg(OH)2 formed

19
Q

Test for ammonium ions

A

add NaOH
warm it
gas turns dam red litmus paper blue it indicates ammonium ions were present

20
Q

ionic equation for NaBr and silver nitrate

A

Ag+ (aq) + Br-(aq) —-> AgBr(s)

21
Q

why is the silver nitrate test used to identify used to identify halide ions

A

produces precipitate that are easily identified by colour

22
Q

Fluoride reaction with ammonia
colour of precipitate

A

No reaction
no colour

23
Q

Chloride reaction with ammonia
colour of precipitate

A

colour: white ppt
reaction: Dissolve in dilute ammonia

24
Q

Bromide reaction with ammonia
colour of precipitate

A

colour: Cream ppt
reaction: Dissolve in concentrated ammonia

25
Q

Iodide reaction with ammonia
colour of precipitate

A

colour: yellow ppt
reaction: insoluble in concentrated ammonia

26
Q

why is dilute nitric acid added before the silver nitrate for a halide test

A

to remove soluble carbonate and hydroxide ions would give a false +ve result

27
Q

describe how you would carry out the halide test

A
  1. Dissolve sample in water
  2. Add HNO3
  3. Add AgNO3 solution
  4. Change in colour
  5. Add dilute NH3
  6. Add conventrayed NH3
28
Q

write half equations for the formation of the 3 sulfur-contacting reduction products of this reaction

A

H2SO4 + 2H+ + 2e- –> SO2 + 2H2O

H2SO4 + 6H+ + 6e- —> S + 4H2O

H2SO4 + 8H+ + 8I- —> H2S + 4H2O

29
Q

write a redox equations for the formation of the 3 sulphur- containing reductions products of this reaction

A

H2SO4 + 2H+ + 2I- —> SO2 + 2H2O + I2

H2SO4 + 6H+ + 6I- —-> S + 4H2O + 3I2

H2SO4 + 8H+ + 8I- —> H2S + 4H2O + 4I2

30
Q

Name the products formed when solid NaI reacts with concentrated sulphuric acid and state the observations you would make upon their formation

A

steamy fumes of HI
black solid of I2
Bad eggs smell caused by H2S
yellow solid of S
colourless solution of NaHSO4

31
Q

Write equation for the precipitates

A

Ag+ + I- ——> AgI
Ag+ + Br- ——> AgBr
Ag+ + Cl- ——> AgCl

32
Q

Equation for NH3 with
AgCl
AgBr

A

AgCl + 2NH3 ——> Ag(NH3)2 +Cl-
AgBr + 2NH3 ——> Ag(NH3)2 +Br-

33
Q

Cl is often added to water because it….

A

Sterelises wate4 by killing bacteria

CHEMISTRY (23 decks)

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