Science, Technology, Engineering and Mathematic Schools
Mid Term Exam
2015– 2016
Subject: Chemistry
Grade
2
Time: 60 minutes
Instructions
Use Blue ink, ballpoint pen or pencil.
Answer all questions.
Answer the questions in the spaces provided –there may be more space
than you need.
Information
You can use the BLANK PAGE at the end of the questions as draft papers.
Candidates may use a scientific calculator.
Advice
Read each question carefully before you start to answer it.
Keep an eye on the time. Try to answer every question.
If you do not know the answer to a question, go on to the next question.
You may come back to the skipped question later if you have time.
Check your answers if you have time at the end.
1
LO.CH.2.01
- If you have 1500g of clothes bleach and the percent by mass of it is
3.62%, then what is the mass of NaOCl in the solution?
A- 54.3g
B- 0.54g
C- 5.43g
D- 543g
Subject _ Grade
Page2 of 13
2
LO.CH.2.02
The graph shows the relationship between pH value and hydronium ion
concentration for common aqueous solutions and mixtures. According to this
graph what is the hydronium ion concentration of tomato juice?
A- 0.00001 M.
B- 4 M.
C- 0.0001 M
D- 0.001 M.
3
LO.CH.2.01
Which aqueous solution has the lowest freezing point?
A- 1.0 M NaCl.
B- 1.0 M C H O .
C- 1.0 M C H OH.
D- 1.0 M CH COOH
Subject _ Grade
Page3 of 13
4
S
LO.CH.2.01
Solubility data for four different salts in water at 60 q
C are shown in the table
below. Which salt is most soluble at 60 q
C?
Solubility on Water at 60 0C
10 grams/ 50 grams H O
20 grams/ 60 grams H O
30 grams/120 grams H O
40 grams/ 80 grams H O
Salt
A
B
C
D
A- salt A.
B- salt B
C- salt C.
D- salt D.
LO.CH.2.02
5
A solution made by dissolving 9.81 g of a nonvolatile non electrolyte in
90.0 g of water boiled at 100.37 oC at 760 mm Hg. What is the
approximate Molecular Mass of the substance?
(For water Kb = 0.51 oC/m)
A-
240,66 g/mol
B-
140.32 g/mol
C-
150.24 g/mol
D-
161.67 g/mol
Subject _ Grade
Page4 of 13
6
LO.CH.2.02
A solid substance was tested in the laboratory. The test results are listed
below.
•dissolves in water
•is an electrolyte
•melts at a high temperature.
Based on these results, the solid substance could be:
A- Cu.
B- CuBr .
C- C H O .
D- C.
7
LO.CH.2.01
Given the solubility graph shown below: How many grams of potassium bromide
(KBr) can be expected to dissolve in 50 grams of water at a temperature of 70 0C?
A- 30 grams
B- 15 grams.
C- 90 grams.
D- 45 grams.
Subject _ Grade
Page5 of 13
LO.CH.2.02
8
As
A student was studying the pH differences in samples from two streams, A and B.
The student measured a pH of 4 in stream A and a pH of 6 in stream B. Compared
to the hydronium ion concentration in stream A, stream B contains:
A- Two times more hydronium ions.
B- 100 times fewer hydronium ions.
C- 100 times more hydronium ions.
D- Two times fewer hydronium ions.
LO.CH.2.01
9
Mole fraction of 10% urea is:
A-
0.042
B-
0.023
C-
0.031
D-
0.072
(Molar mass of urea = 60 g/mol )
LO.CH.2.02
10
What is the safest method for diluting concentrated sulfuric acid with water?
A-
Add the water to the acid slowly while stirring.
B-
Add the acid to the water slowly while stirring.
C-
Add the water to the acid quickly.
D-
Add the acid to the water quickly.
Subject _ Grade
Page6 of 13
11
LO.CH.2.01
A student wants to prepare a 1.0-liter solution of a specific molarity. The student
determines that the mass of the solute needs to be 30. grams. What is the proper
procedure to follow?
A-
Add 1,000. g of solvent to 30. g of solute.
B-
Add 30. g of solute to 970. mL of solvent to make 1.0 L of solution.
C-
Add 30. g of solute to 1.0 L of solvent.
D-
Add enough solvent to 30. g of solute to make 1.0 L of solution.
LO.CH.2.02
12
A A student conducted an experiment testing various solutions. The results appear
in the data table below. Based on the data table, which solution could be NaOH?
Color upon addition of
phenolphthalein
colorless
pink
colorless
pink
A-
solution X.
B-
solution Y.
C-
solution Z.
D-
solution W.
Subject _ Grade
Electrical
conductivity
poor
poor
good
good
Solution
W
X
Y
Z
Page7 of 13
LO.CH.2.01
13
Why does a powdered aspirin dissolve more quickly than tablets in water of
the equal amount of aspirin at same temperature?
A- The concentration of the aspirin tablet is larger.
B- The surface area of the aspirin tablet is larger.
C- The concentration of the powdered aspirin is larger.
D- The surface area of the powdered aspirin is larger.
LO.CH.2.02
14
What is the H O ion concentration of a solution that has an OH ion
concentration of 1.0 x10 M?
A- 1.0 x 10
M
B- 1.0 x 10 M
C- 1.0 x 10
M
D- 1.0 x 10 M
Subject _ Grade
Page8 of 13
LO.CH.2.01
15
In a titration experiment, a student uses a 1.4 M HBr(aq) solution and the
indicator phenolphthalein to determine the concentration of a KOH(aq)
solution. The data for trial 1 is recorded in the table. What is the molarity of
the KOH (aq) solution for trial 1?
KOH(aq)
11.00
33.10
22.10
Trial 1
HBr(aq)
7.50
22.90
15.40
Buret Readings
Initial volume (mL)
Final volume (mL)
Volume used (mL)
A- 0.98 M.
B- 0.46 M.
C- 2.0 M.
D- 240 M.
16
LO.CH.2.01
How many grams of Glucose are in 250ml of a 3M solution?
(The molar mass of glucose is 180g/mol)
A- 166g
B- 137g
C- 180g
D- 135g
Subject _ Grade
Page9 of 13
17
LO.CH.2.01
What is the mass of water added to 255g of salt to make a 15% by mass
solution?
A- 1400g
B- 1445g
C- 1700g
D- 1850g
18
LO.CH.2.02
The vapor pressure of a solution containing a nonvolatile solute is
directly proportional to:
A- Molality of the solvent
B- Osmotic pressure of the solute
C- Molarity of the solvent
D- Mole fraction of solvent
Subject _ Grade
Page10 of 13
19
LO.CH.2.02
Ethylene glycol is mixed with water as anti-freeze in radiator because:
A- It has low vapor pressure
B- It raises the boiling point of water
C- It lowers the freezing point of water
D- It has all characters
20
W
LO.CH.2.02
Which is the pH of a 0.0001 M aqueous solution of HCl?
A- 4
B- 2
C- 1
D- 3
Subject _ Grade
Page11 of 13
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Subject _ Grade
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Subject _ Grade
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