Brainscape's Knowledge GenomeTM

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


See full index

Chemistry > Chemistry 3 > Flashcards

Chemistry 3 Flashcards

1
Q

Why is the periodic table called this?

A

Similar properties occur at regular intervals.

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

What was the first scientist (that we learn about) that came up with a version of the periodic table?

How did he arrange them?

A

John Newsland - 1864

Ordered the elements in order of its atomic weights.

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

What is the second scientist (that we learn about) that came up with a close version of the periodic table?

How did he arrange them?

A

Mendeleev - early 1900

When organising the elements into the table he left gaps for the elements they hadn’t discovered yet.

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

When were neutrons, protons and electrons discovered?

How is the modern periodic table organised?

A

Early 20th Century.

Arranged in order of atomic number. Then all elements were placed into appropriate groups.

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

What are the elements in group one known as?

How dense are these metals?

A

Alkali metals

Low density - the first three are less dense than water

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

What does group one metals react with to create ionic compounds?

A

Non metals - the metal ion carries a charge of +1.

The compounds are white solids that dissolve in water to form colourless solutions

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

What happens if you react water and a group one metal?

A

Hydrogen is released.

A metal hydroxide is formed. These dissolve in water to give an alkaline solution.

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

In group one what is the trends for the;

reactivity?

melting / boiling point?

A

The further down the group an element is the more reactive it becomes.

The further down the group an element is the lower the melting / boiling point is.

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

What are transition metals like, in comparison to group one metals?
[4 points]

A

Higher melting points (except mercury)

Higher densities

Stronger and harder

Much less reactive and so do not react as vigorously with water or oxygen.

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

Transition metals are…

[3 points]

A

Some have ions with different charges
For example Fe^2+ - Fe^3+

Form coloured compounds

Useful as catalysts

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

What are elements in group seven known as?

What happens when they react with a metal?

A

Halogens

Form a ionic compound in which the halide ion carries a charge of -1.

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

In group seven, what are the trends for;

reactivity?

boiling / melting point?

A

The further down the group an element is the less reactive it is.

The further down the group an element is the higher its boiling / melting point is.

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

What happen when there are more than two different halogens?

Example?

A

A more reactive halogen can displace a less reactive halogen from an aqueous solution of its salt.

Cl2 + 2KBr ==> Br2 + 2KCl

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

What is hard water?

What is soft water?

A

Water that contains dissolved compounds like magnesium or calcium. The compounds are dissolved when they come into contact with the rock.

book

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

Soft water + soap =

Hard water + soap =

A

Lather

Scum

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

What are the two types of hard water?

A

Permanent hard water: remains hard when boiled

Temporary hard water: softened by boiling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does temporary hard water contain?

A

Hydrogencarbonate ions - they decompose on heating to produce carbonate ions which react with calcium and magnesium ions to form precipitates.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are some of the negatives using hard water + temporary hard water?

A

More soap is needed for a lather so it increases cost.

When temporary hard water is heated it can produce scale that reduces efficiency of heating systems and kettles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the benefits of hard water?

A

Calcium ions are good for the development and maintenance of bones and teeth; can help reduce the risk of heart disease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

In general how can hard water be made soft?

A

By removing magnesium and calcium ions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the two ways to make hard water sort?

A

Adding sodium carbonate. This reacts with the calcium and magnesium ions to form a precipitate of calcium carbonate and magnesium carbonate.

Using water softeners such as ion exchange columns containing hydrogen ions or sodium ions. This can replace the calcium and magnesium ions when hard water passes through the column.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the correct drinking water quality for humans?

A

Sufficiently low levels of dissolved salts and microbes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How is water of correct quality produced? [three reasons]

A

By choosing an appropriate source.

Passing the water through filter beads to remove any solids.

Sterilising with chlorine.

24
Q

How do water filters remove some substances?

A

Carbon, silver and ion exchange resins can remove some dissolved substances from tap water to improve the taste and quality.

25
Q

What are the benefits of adding chlorine to drinking water?

What are the benefits of adding fluoride to drinking water?

What are the negatives about adding fluoride to drinking water?

A

Reduce microbes (kill off).

Improve dental health (reduce tooth decay).

In high doses adding it can cause cancer and bone problems in humans. Also ethically right? Some believe you should be able to choose it you have fluoride added to the water.

26
Q

How can you produce pure water?

A

Distillation - boiling the water to make steam and condensing the steam. Very expensive because of high energy costs involved.

27
Q

What is energy normally measured in?

A

Joules

28
Q

How do you measure the relative amount of energy released when substances burn?

A

Simple calorimetry.

Such as heating water in a glass or metal container. This method can be used to compare the amount of energy released by fuels and foods.

29
Q

How do you calculate the amount of energy released by different fuels?

A

Q = mc(triangle)T

Energy transferred = mass x SHC x (change in) time

30
Q

How can the amount of energy released or absorbed by a chemical reaction in solution be calculated?

A

The measured temperature change of the solution when the reagents are mixed in an insulated container.
This method can be used for reactions of solids with water or for neutralisation reactions.

31
Q

In relation to energy what should happen during a chemical reaction? [two points]

A

Energy must be supplied to break the bonds.

Energy is released when bonds are formed.

32
Q

What is energy like in relation to an endothermic reaction?

A

The energy released from forming new bonds is greater than the energy needed to break the existing bonds.

33
Q

What is energy like in relation to an exothermic reaction?

A

The energy needed to break existing bonds is greater than the energy released from forming new bonds.

34
Q

What is activation energy?

How do you lower it?

A

The minimum amount of energy required for the reaction to take place.

By a catalyst.

35
Q

How can hydrogen be fuel?

A

Burned as a fuel in combustion engines.

It can also be used in fuel cells that produce electricity to power vehicles.

36
Q

What can flame tests identify?

What five substances specifically and what colour do they turn?

A

Metal ions.

Lithium compounds turn crimson
Calcium compounds turn red
Barium compounds turn green
Sodium compounds turn yellow
Potassium compounds turn lilac
37
Q

How do you find positive ions?

What are the outcomes?

A

Add sodium hydroxide.

Copper forms a blue precipitate.
Iron (II) forms a green precipitate.
Iron (III) forms a brown precipitate.

Magnesium, Aluminium and Calcium form a white precipitate.
Aluminium dissolves in excess sodium hydroxide.
Flame test to differentiate calcium and magnesium.

38
Q

How do you test for carbonate ions?

What is the outcome?

What is the formula?

A

Add dilute acid to the sample.

If its a carbonate ion it will form carbon dioxide which produces a white precipitate with limewater. Turning limewater cloudy.

Acid + Carbonate –> Salt + Water + Carbon dioxide

39
Q

How do you test for a halide ion?

What would the outcomes be?

A

Add dilute nitric acid, followed by silver nitrate solution.

Chloride gives a white precipitate of silver chloride.
Bromide gives a cream precipitate of silver bromide.
Iodide gives a yellow precipitate of silver iodide.

40
Q

How do you test for sulfate ions?

What would the outcomes be?

A

Add dilute Hydrochloric acid, followed by barium chloride solution.

If there was a sulfate ion present there would be a white precipitate of barium sulfate.

41
Q

What is a titration measuring?

Example?

A

It measures the volumes of acid and alkali solutions that react with each other by using titration and a suitable indicator.

For example exactly how much acid is needed to neutralise a quantity of alkali.

42
Q

What are the steps in titration when wanting to find the exact volume of acid is needed to neutralise an alkali?

A
  1. Use a pipette to exactly measure the amount of alkali then put it into a conical flask.
  2. Add a few drops of a suitable indicator into the conical flask. (This is to show a change of colour when products have reacted)
  3. Add the acid into the burette.
  4. The acid is added to the flask one drop at a time, whilst swirling the flask, to see accurately when the alkali has be neutralised.
  5. Record information.
43
Q

How do you find the number of moles in a substance?

How do you find the concentration of a reactant during titration?

A

Mass x Relative formula mass = Number of moles
m / Mr = n

Number of Moles / Volume = Concentration
n / V = c

44
Q

What are the units for concentration?

A

moles per dm^3 (mol/dm^3)

g/dm^3

45
Q

What are the materials used in the Haber process?

Where have they come from?

A

Nitrogen + Hydrogen

N - obtained from air
H - obtained from natural gases or other sources

46
Q

How does the Haber process work?

A

The purified gases are passed over a catalyst of iron at the temperature of 450 degrees and a high pressure of 200 atmospheres.
Some of hydrogen and nitrogen reacts to form ammonia.
While cooling , the ammonia liquefies and is removed. The remaining hydrogen and nitrogen is recycled.

47
Q

What is a closed system?

What happens when a reversible reaction occurs in a closed system?

A

When no substances can enter or leave the reaction.

Equilibrium is reached when the reactions occur at exactly the same rate in each direction.

48
Q

What is equilibrium?

A

The point in a reversible reaction where the forward and reverse rates of reaction are the same.
Making the same amount of product and reactant.

49
Q

What happens when you increase the pressure in gaseous reaction?

A

It will favour the reaction the produces the least number of molecules. (symbol equation)

50
Q

What happens when the temperature is raised in a reversible reaction?

A

The yield for the endothermic reaction increases and the yield for the exothermic reaction decreases. Visa versa.

51
Q

What is the functional group for alcohol?

What are the first four alcohols in the homologous series?

A

-OH

Methanol, ethanol, propanol + butanol

52
Q

What are some of the properties of methanol, ethanol + propanol?

A

Dissolve in water to form a neutral solution.

React with sodium to produce hydrogen.

Burn in air.

Used as fuels and solvents, and ethanol is the main alcohol used in alcoholic drinks.

53
Q

What happens when you oxidise ethanol?

A

It becomes ethanoic acid, by chemical oxidising agents or by microbial action. Ethanoic acid is the main acid in vinegar.

54
Q

What are the carboxylic acid function group?

What are the first three names?

A

-COOH

Methanoic, ethanoic + propanoic

55
Q

What are the properties of carboxylic acids?

A

Dissolve in water to produce acidic solutions.

React with carbonates to produce carbon dioxide.

React with alcohol in the presence of an acid catalyst to produce an ester.

56
Q

What are esters functional group?

What is ethyl ethanoate?

What are they used for?

A

-COO-

The ester produced from ethanol and ethanoic acid.

Volatile compounds with distinctive smells so are used for flavourings and perfumes.

57
Q

carboxylic acids

A

do not ionise completely when dissolved in water and so are weak acids

aqueous solutions of weak acids have a higher pH value than aqueous solutions of strong acids with the same concentration

Chemistry (3 decks)

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