CHE1501/201/1/2020
Tutorial letter 201/1/2020
General Chemistry 1A
CHE1501
Semester 1
Department of Chemistry
Define tomorrow.
,CONTENTS
1 KEY TO ASSIGNMENT 01........................................................................................................... 3
2
, CHE1501/201/1/2020
1 KEY TO ASSIGNMENT 01
QUESTION 1
A mixture is composed of two or more types of matter that can be present in varying amounts and can be
separated by physical changes, such as evaporation. Examples include, Orange juice, Coca-Cola, and
pancake syrup are mixtures that contain sugar. The amount of sugar varies from one to another because the
composition can vary from one mixture to another. Mixtures can be either homogeneous or heterogeneous.
A mixture is made up of different compounds and not only elements.
Therefore, the correct answer is 4: A mixture must contain at least two different substances
QUESTION 2
Mixtures can be either homogeneous or heterogenous. A homogeneous mixture has the same properties
throughout the sample. e.g; a thoroughly stirred mixture of sugar and water or salt and water, also called a
solution. Solutions need not be liquid, just homogeneous. e.g; clean air is a gaseous solution mixture of
oxygen, nitrogen and a number of other gases. A heterogenous mixture consists of two or more regions
called, phases, that differ in properties. e,g, mixture of oil and vinegar, for example is a two phase mixture in
which oil floats on the vinegar as a separate layer. A mixture of liquid water and ice is a two-phase
heterogenous mixture, in which the phases have the same chemical composition but occur in different
physical states.
Therefore, the correct answer is 5: Soil is an example of a heteregonous mixture since it may contain some
powered material, and rocks. However, Cola (NOT carbonated cola or Fizzy coke), Brass, Air and Coffee
with sugar stirred in, are all examples of homogeneous mixture. Fizzy coke or carbonated cola is
heterogeneous because some of the mixture is liquid and some is bubbles.
QUESTION 3
Density = mass / volume = 46.6 g / 5.2 cm3 = 9.0 g/cm3
The answer is reported to two significant figures. In a multiplication or division, the final answer is
reported to the least number of significant figures as there in any of the original values. 46.6 has 3
significant figures while 5.2 has two significant figures, so the answer is reported to the least number of
3
Tutorial letter 201/1/2020
General Chemistry 1A
CHE1501
Semester 1
Department of Chemistry
Define tomorrow.
,CONTENTS
1 KEY TO ASSIGNMENT 01........................................................................................................... 3
2
, CHE1501/201/1/2020
1 KEY TO ASSIGNMENT 01
QUESTION 1
A mixture is composed of two or more types of matter that can be present in varying amounts and can be
separated by physical changes, such as evaporation. Examples include, Orange juice, Coca-Cola, and
pancake syrup are mixtures that contain sugar. The amount of sugar varies from one to another because the
composition can vary from one mixture to another. Mixtures can be either homogeneous or heterogeneous.
A mixture is made up of different compounds and not only elements.
Therefore, the correct answer is 4: A mixture must contain at least two different substances
QUESTION 2
Mixtures can be either homogeneous or heterogenous. A homogeneous mixture has the same properties
throughout the sample. e.g; a thoroughly stirred mixture of sugar and water or salt and water, also called a
solution. Solutions need not be liquid, just homogeneous. e.g; clean air is a gaseous solution mixture of
oxygen, nitrogen and a number of other gases. A heterogenous mixture consists of two or more regions
called, phases, that differ in properties. e,g, mixture of oil and vinegar, for example is a two phase mixture in
which oil floats on the vinegar as a separate layer. A mixture of liquid water and ice is a two-phase
heterogenous mixture, in which the phases have the same chemical composition but occur in different
physical states.
Therefore, the correct answer is 5: Soil is an example of a heteregonous mixture since it may contain some
powered material, and rocks. However, Cola (NOT carbonated cola or Fizzy coke), Brass, Air and Coffee
with sugar stirred in, are all examples of homogeneous mixture. Fizzy coke or carbonated cola is
heterogeneous because some of the mixture is liquid and some is bubbles.
QUESTION 3
Density = mass / volume = 46.6 g / 5.2 cm3 = 9.0 g/cm3
The answer is reported to two significant figures. In a multiplication or division, the final answer is
reported to the least number of significant figures as there in any of the original values. 46.6 has 3
significant figures while 5.2 has two significant figures, so the answer is reported to the least number of
3
