Measurement in Chemistry Flashcards

1
Q

What are the 5 instruments for measuring the volume of liquids.

A

Beaker, pipette, burette, measuring cylinder, conical flask.

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

What are 2 typical sizes of beakers and conical flask.

A

100 cm3 and 250 cm3

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

What is one advantage that conical flask have over beakers?

A

Using the beaker, it reduces the chance of spillage of liquid due to its small mouth opening.

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

How accurate are measuring cylinder up to?

A

They are accurate only to 0.5 cm3. Hence, they are not used for very accurate measurement of volumes.

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

What are the 4 typical sizes of measuring cylinder?

A

10.0cm3, 25.0cm3, 50.0cm3, 100.0cm3

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

What is the accuracy of (a) pipette and (b) burette.

A

(a) 0.1cm3

(b) 0.05cm3

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

is Ammonia acidic or alkaline?

A

Alkaline

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

Describe a reason to explain why ammonia cannot be collected by the displacement of water?

A

This is because ammonia is extremely soluble in water. A highly soluble gas cannot be collected by this method because it can dissolve in water completely.

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

What are the 4 physical properties of measurement?

A

Time, mass, temperature and volume.

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

What is the SI name and unit for time?

A

SI name: seconds

SI unit: s

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

What is the SI name and unit for temperature?

A

SI name: kelvin

SI unit: K

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

What is the SI name and unit for mass?

A

SI name: kilogram

SI unit: kg

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

What is the SI name and unit for volume?

A

SI name: cubic metre

SI unit: m3

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

What is the function of the gas syringe?

A

It is used to collect and measure the volume of gases of any density.

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

What is the function of a burette?

A

It is to measure the volume of a solution accurately with a accuracy of 0.1cm3.

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

What is the function of the pipette?

A

The pipette is used to deliver an accurate fixed volume of a solution.

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

What is the difference between the burette and the pipette?

A

A pipette can only measure fixed volume, such as 20.0cm3. Odd volumes such as 21.0cm3 and 22.3 cm3 cannot be measured.

On the other hand, burette can measure any volume of liquids up to 50.0 cm3. Odd values such as 23.80cm3 or 27.68 cm3 can be measured.

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

What are the typical sizes of pipettes.

A

20.0 cm3, 25.0 cm3 and 50.0 cm3.
Pipettes come in fixed sizes There is only 1 marking for each pipette. Hence, they can only be used to measure fixed volumes.

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

What is the maximum capacity of a gas syringe?

A

100 cm3.

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

What is the function of the measuring cylinder?

A

It is to measure approximate amount of volume of a solution.

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

What is the function of the beaker?

A

It is to measure a approximate amount of volume of a solution.

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

what is a meniscus?

A

Meniscus is the surface of the liquid that curves at the side of the measuring instrument.

23
Q

What are the 3 methods for the collection of gas?

A

Displacement of air, displacement of water and gas syringe.

24
Q

What is the principal that allows a gas to be collected by the displacement of air?

A

The principal is that the gas collected has to be of densities higher or lower than air. It is not suitable for collecting gas with a density same as air.

25
Q

What are the 2 types of displacement of air?

A

Upward delivery and downward delivery.

26
Q

What is the difference between using upward delivery and downward delivery?

A

Upward delivery is used for gas which are less dense than air.

Downward delivery is used for gas which are denser than air.

27
Q

What is the position of the test tube when in (a) upward delivery and (b) downward delivery.

A

(a) upright position

(b) inverted position

28
Q

Explain how the process of collecting gas in an upward delivery works.

A

In the process of the upward delivery, the test tube is placed in a upward position. Gas which are less dense than air would rise and displaces the air in the test tube. Hence collecting the gas.

29
Q

Explain how the process of collecting gas in a downward delivery works.

A

In the process of a downward delivery, the test tube is being placed in a inverted position. Gas which are denser than than air would sink, and displaces the air inside it. Hence collecting the gas.

30
Q

Examples of gas being collected through upward delivery.

A

Hydrogen and ammonia.

31
Q

Examples of gas being collected through downward delivery.

A

Chlorine, hydrogen chloride, sulfur dioxide, carbon dioxide, nitrogen dioxide.

32
Q

What are 2 physical properties of a gas that will determine its method of collection?

A

1) Solubility of the gas in water.

2) Density of the gas.

33
Q

What are the considerations needed to make before using the process “Displacement of water”.

A

Gases which are:
1) Insoluble or only slightly soluble in water. [Cannot dissolve in water]

2) Has density almost the same as air. (which displacement of air cannot take place)

34
Q

Name gases which are soluble in water.

A

Chlorine, hydrogen chloride, sulfur dioxide, ammonia.

35
Q

Name gases which are insoluble in water.

A

hydrogen, oxygen and carbon dioxide.

36
Q

When will the method “Displacement of water” cannot be used?

A

It is if the gas is soluble in water. As it will dissolve in water and thus cannot be displaced.

37
Q

What is the function of drying agent?

A

The drying agent is used to obtain a dry sample of gas by removing the moisture content.

38
Q

What does it mean by “Moisture content” in chemistry?

A

Moisture content is, simply, how much water is in a product. It influences the physical properties of a substance, including weight, density, viscosity, conductivity, and others. It is generally determined by weight loss upon drying.

39
Q

What are the 3 common types of drying agents used in laboratory to dry gases.

A

Anhydrous calcium chloride (Fused calcium chloride), Concentrated sulfuric acid and Calcium oxide (quicklime).

40
Q

What is the gas that cannot be dried under anhydrous calcium chloride?

A

Ammonia (NH3)

41
Q

What is the gas that cannot be dried under concentrated sulfuric acid?

A

Alkaline gases such as ammonia (NH3)

42
Q

What is the type of gas that cannot be dried under quicklime?

A

Acidic gases such as sulfur dioxide (SO2).

43
Q

Examples of gas being dried under concentrated sulfuric acid?

A

Sulfur dioxide, chlorine, hydrogen chloride and carbon dioxide.

44
Q

Examples of gas being dried under calcium oxide?

A

Ammonia NH3

45
Q

Examples of gas being dried under fused calcium chloride.

A

Hydrogen, oxygen and ammonia.

46
Q

Complete the sentence:
As a general rule, concentrated sulfuric acid is used to dry (a) or (b) gases. Concentrated sulfuric acid is not used to dry (c) gases, as it is acidic in nature and will react with such gases rather than drying them.

A

(a) Acidic
(b) neutral
(c) Alkaline

47
Q

Complete the sentence:
Calcium oxide is used to dry (a) or (b) gases. Calcium oxide (quicklime) is not used not used to dry (c) gases as it is alkaline in nature and will react with such gases rather than drying them.

A

(a) Alkaline
(b) Neutral
(c) acidic

48
Q

Complete the sentence:

Fused calcium chloride is used to dry a (a) of gases. It is (b) in nature (i.e neither acidic nor alkaline).

A

(a) Variety

(b) Neutral

49
Q

What is the advantage of a data logger?

A

Data logger can measure temperature over seconds, it is more accurate than mercury/ alcohol thermometer, and it records data continuously.

50
Q

What is the accuracy of temperature taken by thermometers?

A

+/- 0.5 degree Celsius

51
Q

Are beakers and conical flask used for measurements?

A

No they are not. They are suppose to act as a container.

52
Q

Exact/ Accurately ->

A

Burette/ pipette

53
Q

Approximately ->

A

Measuring cylinder (1.d.p)