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Electrolyte and pH questions
1.
Alice frequently uses a white cleaning powder in her home. She wants to know whether
this substance is acidic, basic or neutral. In order to determine the pH of this substance,
what is the first thing she must do?
A) Put a piece of blue litmus paper on the solid.
B) Put a piece of red litmus paper on the solid.
e) Verifv whether the solid conducts electricity.
Oissotve a small amount of the solid in water.
@
2.
Which of the following are acids?
HI
NaCl
HCH:COz
HCl
KOH
LiF
CaClz
NH+OH
C)5,6and8
A) 1,5 and
D) 3,4 andT
and
1.
2.
a
J.
4.
8
6
WL5
1.
2.
3.
3.
4.
5.
6.
7.
8.
Which of the following are bases?
BeO
NaOH
HI
HCl
KOH
LiF
CaClz
AF+oH
C)3,5and6
\4J) 1, 4 and
D) 1,3 and 7
B) 2,3 and
7
8
5.
6.
7.
8.
4.
Which of the following describes a neutral salt solution?
A) A solution that does not conduct elechicity and that does not change the colour of
,-\- litmus paper
( B\ A solution that conducts electricity and that does not change the colour of litmus
- \_/
paper
C) A solution that conducts electricity
D) A solution that conducts electricity
and that turns litmus paper red
and that turns litmus paper blue
5.
234s6789101112
nH Scale
Indicator
I
Yellow
Indicator
2
Colourless
Indicator
3
Red
Indicator
4
Red
Blue
Green
Orange
Pink
Fuchsia
Yellow
Orange
The pH of a given solution is unknown. lndicators 1 and 3
What colour will indicator 4 become in this solution? r\,
Green
Yellow
tum yellow in this solution.
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6- You have been given a sample of water taken from a swimming pool. You a.re to
determine whether this water is acidic, basic or neutral.
.-\
The materials available are
- a graduated cylinder containing 15 mL of vinegar (pH:2.8)
- a graduated cylinder containing 15 mL of ammonia (pH: 11)
- a graduated cylinder containing 15 mL of pure water (pH: 7)
- a small bottle of bromothymol blue without a colour chart
Write the experimental procedure you would follow to determine whether the water is acidic,
basic or neutral, using the materials available. /5
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The following table gives the colours of two acid-base indicators when they are added to
solutions with
w1 different pH val
alues.
1
pH Scale
lndicator
1
Indicator
2
Red
Yellow
3
5
7
Orange
Yellow
Green
9
t1
13
Blue
A student mixed these two acid-base indicators together and added a few drops of this *irture to
solutions A and B. The pH of solution A is 2 and the pH of solution B is 13. What was the
colour of solution A and the colour of solution B after the mixture was added to each solution?
A) Solution A is red and solution B is yellow.
B) Solution A is yellow and solution B is blue.
@ Sotutlon A is lrurg" and solution B is green.
D) Solution A is red and solution B is blue.
8.
A)
.E)
Q)
D)
Which of the following procedures can be used to determine whether sugar is an
electroly.te or a non-electrolyte?
Check the electrical conductivity of a cube of sugar.
Chect< the electrical conductivity of powdered sugar.
Check the electrical conductivity of an aqueous sugar solution.
Check the electrical conductivity of a heterogeneous mixture of sugar and alcohol.
g. ln the lab, you are given two acidic solutions.
One has a pH value of 5, and the
you to distinguish between
other has a pH value of 6.g-. Name the best indicator that would allow
the two solutions?
hvl
5
6 7 8 9 10 li
4
5
8 9
67 -fbl,,.
Gr"*
3) Phenolphthaletn
.,
4
2
PH 1
Colourless
5
6
oH
2
1
red
nfh
,\a
#rt 12
a
J
4
Oranse
hlrre
3
Yellow
'7
3 4 s 67
8
t2
yellow
13
t4
10
11
T2
13
l4
10
11
l2
13
t4
9
pink
dark pink
8 910 11 12 13
14
Yellow
following statements is false?
A) Like acids and bases, silts conduct an electric current in an aqueous solution'
gi Untit<e acids and bases, salts do not affect neutral litmus paper in an aqueous solution'
ffi' Like acids and bases, salts do not dissolve in water'
f5t Untite acids and bases, salts conduct electricity in a solid state'
10. Which of the
\2
1
pH
below indicates the colour of the indicator phenol red in solutions with a
varying from 1 to 12.
1. The table
A drop of this indicator is added to some lemon juice'
What colour is the indicator after being added to the lemon
juice?
1e,[
[Cn";
\
I
12.In order to classify three unknown solutions as acids, bases or salts, you have been given
the followins
wln infonnati on:
Soiution
1
2
3
Electrical conductivitv
ves
yes
yes
Reaction of blue litmus oaoer
turns red
stavs blue
stays blue
Reaction of red litmus naoer
stays red
stavs red
turns blue
hrformation
On the basis of this information, how do you classify the three solutions?
A)
Solution 1
f,81; Solution
solution t
D) Solution 1
1
$
acid
acid
base
base
Solution 2
Solution 2
Solution 2
Solution 2
base
salt
acid
salt
Solution
Solution
Solution
solution
3
salt
3
base
3
salt
acid
3
13. Which of the following are characteristic properties of a basic solution?
1. Conducts electricity
2. Does not conduct electricity
3. Tums litmus paper blue
4. Turns litmus paper red
5.rffis
not change the colour of litmus paper
(A)I1and3
B)1and4
C)2and3
D)2and5
The following table gives the behaviour of four acid-base indicators.
pH
23
Indicator W
Yellow
Indicator X
Blue
Indicator Y
Red
Indicator Z
Colourless
4 5
6
7
8
9
10
t1
12
Red
Yellow
Purple
a- Which indicator is the only one that can identify a solution as strongly acidic?
b- Which indicator would you use to find a strong base?'/c- What is the pH if indicator X is yellow and indicator Y is red? ft
d- What is the pH if indicator W is red and indicator X is blue? 5
e- what is the colour produced if indicator y has a pH of 12? ptl,( pL6
Yellow