CHM103 TMA1 Answers





Q1 Which of the following statements is true about compounds and mixtures?
Both mixtures and compounds always contain a fixed proportion of elements by mass.
Unlike compounds, very little or no exchange of energy occurs during the formation of mixtures.
A mixture cannot be easily separated into its constituents while constituents of a compound can be easily
separated.
Compounds and mixtures can be separated into its constituents by chemical methods.

Q2 What is a compound?
A substance which contains two or more elements physically combined together in fixed ratio.
A substance which contains only metallic and non-metallic elements chemically joined together.
A substance which cannot be separated into its simpler substances by heating alone.
A substance which is made up of two or more elements chemically joined together.

Q3 Which of these is an amorphous solid?
Glass
Diamond
Graphite
Sodium chloride

Q4 Which of these mixtures is not a nearly ideal liquid mixture?
n-hexane and n-heptane
benzene and toluene
water and ethanol
carbon tetrachloride and silicon tetrachloride

Q5 Which of these is not crystalline
Diamond
Polythene
Potassium iodide
Graphite
Q6 A liquid that has high viscosity flows ____________.
slowly
rapidly
freely
briskly

Q7 A container with volume 71.9 ml contains water vapor at a pressure of 10.4 atm and a temperature
of 465oC. How many grams of the gas are in the container?
0.421 g
0.183 g
0.129 g
0.222 g

Q8 Which one of the following can be separated by adding water, stirring and filtering?
Copper and tin
Salt and sugar
Sulfur and sugar
Salt and copper sulphate

Q9 A mixture of graphite and diamond constitutes __________ phases.
one
two
three
four

Q10 The molarity of urea in a solution prepared by dissolving 16 g of urea (MW = 60.0 g/mol) in 39 g
of H2O is __________ M. The density of the solution is 1.3 g/mL.
0.11
3.7
6.8
6.3

Q11 The mole fraction of He in a gaseous solution prepared from 4.0 g of He, 6.5 g of Ar, and 10.0 g of
Ne is __________.
0.6
1.5
0.2
0.11

Q12 Which of these describes what happens when water freezes?
a phase change occurs from a liquid phase to a solid phase
an exothermic process occurs where energy is lost from ice to the surroundings
the liquid water changes from a random structure to a crystalline solid
all of the above

Q13 In filtration, the term ‘filtrate’ refers to
the solid that remains on the filter paper
the liquid that drains through the filter paper.
the type of filter paper used.
the mixture before separation

Q14 A gas occupies a volume of 2.4 L at 14.1 kPa. What volume will the gas occupy at 84.6 kPa?
497 L
2.5 L
14 L
0.40 L

Q15 The gaseous mixture is a ___________ phase system.
one
two
three
four

Q16 Standard temperature and pressure (STP) refers to which conditions?
0 K and 1 KPa
(b) 0 K and 1 mmHg
273 k and 1 atm
0 K and 1 atm

Q17 Fractional distillation cannot be used to
separate the components of liquid air
refine crude oil
test the purity of a substance
separate methanol and water

Q18 The density of a crystal depends on all the following except
Number of atoms
Its mass
Its geometry
Volume of the unit cell

Q19 Which of these assumes the shape of its container?
Solid
Liquid
gas
vapor

Q20 One of the followings is not true of liquids
The inability of a liquid to flow enables it to assume the shape of the container
A liquid never expands to fill the container
The characteristics of a liquid lie between those of a solid and a gas
Particles of liquid are free to move from one point to another

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