Ch1: Experimental Chemistry Flashcards

1
Q

A mixture is made up of…

A

Two or more substances that are not chemically combined

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

Air’s density

A

32
O2 –> (Mr (16) x (2))

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

To separate a mixture of two solids, we use a solvent in which one solid is _______ (The other is _______ in that ______)

A

soluble and insoluble in that solvent

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

substances can turn straight into a gas on heating, without becoming a liquid first
what is this called?

A

sublimation

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

A pure substance is made up of…

A

One single element or compound. It is not mixed with any other substance.

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

A mixture is made up of..

A

Two or more substances that are not chemically combined together

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

Some substances can turn straight into gas on heating, without becoming a liquid first. This is called….

A

Sublimation

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

Sublimation is used to separate a solid that….. from one that does not.

A

Sublimes.

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

Sublimation can he used to separate____ mixtures such as….

A

Solid-solid, ammonium chloride and sodium chloride.

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

Sublimation test:
A mixture is placed in an evaporating dish with an inverted funnel on the top. It is then gently _____.
The ammonium chloride _____ and changed directly to a _____ which _____ back to a ______on the cold glass funnel.
What remains in the evaporating dish?

A

Heated
Sublimes, gas, cools
Sodium chloride

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

A mixture made of solid particles of different sied can be separated by….

A

Sieving

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

…….. can be used to separate a magnetic substance from a non-magnetic substance.

A

Magnetic attraction

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

Meaning of the term ‘solute’
E.g. …..

A

Substance that dissolves ______.

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

The liquid that the substance dissolves in

A

Solvent

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

Characteristics of solutions

A

Clear. Some may be coloured (e.g. brown, blue, green) or have no colour (colourless)

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

Filtration is used to separate an…… from a liquid. a funnel lined with filter paper is usually used.

A

Insoluble solid

17
Q

……. is used to separate a soluble solid from a liquid.

A

Evaporation

18
Q

……. is a process of obtaining a soluble solid from a solution by heating the solution until all the water has boiled off

A

Evaporation to dryness

19
Q

Process of evaporation to dryness

A

Obtaining a soluble solid from a solution by heating the solution until all the water has boiled off

20
Q

If we heat the solution so that only some of the solvent vaporises, and then leave the hot saturated solution to cool, some of the solid reappears as pure …….
this is called……

A

Crystals, crystalization

21
Q

Simple distillation is used to separate the …….(liquid) from a solution

A

Solute

22
Q

Boiling chips are added to

A

Ensure smooth boiling

23
Q

As the solution boils, vapour rises. If distillation is allowed to carry on, ……

A

a solid residue of the salt will be left in the flask

24
Q

The condensed water in simple distillation in the conical flask is called the….

A

Distillate

25
Q

The separating funnel is used to….

A

Separate two liquids which do not mix together

26
Q

Mixtures that do not mix together are…

A

Immiscible

27
Q

In the separating funnel, when the tap is opened, what drained?

A

The densest layer is allowed to drain into the beaker.

28
Q

Process of separating a mixture of miscible liquids which dissolve in ……

A

Chromatography, same solvent

29
Q

Process of separating dyes in food colouring, ink or pigments

A

Paper chromatography to a chromatogram

30
Q

Some solutes are less soluble in the solvent and thus does not travel very far across the paper. What does this show?

A

Difference in solubility allowing the dyes in the food colouring to be separated

31
Q

Process of separating a mixture of miscible liquids with different boiling points.

A

Fractional distillation

32
Q

In fractional distillation, explain what is happening in the fractionating column

A

The liquid with the lower boiling point passes into the condenser. Higher boiling point condenses and falls back into the flask.

33
Q

What does presence of impurities do to the melting points?

A

Increases the melting points, causing the substance to melt over a range of temperatures.

34
Q

Suitable drying agent for carbon dioxide

A

Fused calcium chloride.

35
Q

Suitable drying agent for Ammonia

A

Quicklime (calcium oxide)

36
Q

Suitable drying agent for Hydrogen

A

Fused calcium chloride

37
Q

Fused calcium chloride. It readily absorbs moisture from the air, So it must be…

A

Freshly heated before use

38
Q

Quicklime (calcium oxide) absorbs moisture and carbon dioxide from the air, so it must be…

A

Freshly heated before use