Download 1. What is the sum of all coefficients when the following

1.
What is the sum of all coefficients when the following equation is balanced using the smallest possible
whole numbers?
__ C2H2 + __O2 → __CO2 + __H2O
A.
5
B.
7
C.
11
D.
13
(Total 1 mark)
2.
How many molecules are present in a drop of ethanol, C2H5OH, of mass 2.3 × 10
23
–1
(L = 6.0 × 10 mol )
A.
3.0 × 10
B.
3.0 × 10
C.
6.0 × 10
D.
6.0 × 10
–3
g?
19
20
20
26
(Total 1 mark)
3.
3
1.7 g of NaNO3 (Mr = 85) is dissolved in water to prepare 0.20 dm of solution. What is the
–3
concentration of the resulting solution in mol dm ?
A.
0.01
B.
0.1
C.
0.2
D.
1.0
(Total 1 mark)
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1
4.
Which statement about the numbers of protons, electrons and neutrons in an atom is always correct?
A.
The number of neutrons minus the number of electrons is zero.
B.
The number of protons plus the number of neutrons equals the number of electrons.
C.
The number of protons equals the number of electrons.
D.
The number of neutrons equals the number of protons.
(Total 1 mark)
5.
Which property increases down group 1?
A.
First ionization energy
B.
Melting point
C.
Reactivity
D.
Electronegativity
(Total 1 mark)
6.
Which compound forms hydrogen bonds in the liquid state?
A.
C2H5OH
B.
CHCl3
C.
CH3CHO
D.
(CH3CH2)3N
(Total 1 mark)
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2
7.
Which combination of the characteristics of element X, a metal, and element Y, a non metal, is most
likely to lead to ionic bonding?
X
Y
A.
low ionization energy
high electronegativity value
B.
low ionization energy
low electronegativity value
C.
high ionization energy
high electronegativity value
D.
high ionization energy
low electronegativity value
(Total 1 mark)
8.
3
–3
3
–3
When 100 cm of 1.0 mol dm HCl is mixed with 100 cm of 1.0 mol dm NaOH, the temperature of
3
the resulting solution increases by 5.0 °C. What will be the temperature change, in °C, when 50 cm of
these two solutions are mixed?
A.
2.5
B.
5.0
C.
10
D.
20
(Total 1 mark)
9.
Consider the following reactions.
Cu2O(s) +
1
O2(g) → 2CuO(s)
2
Cu2O(s) → Cu(s) + CuO(s)
O
∆H = –144 kJ
O
∆H = +11 kJ
O
What is the value of ∆H , in kJ, for this reaction?
Cu(s) +
A.
–144 + 11
B.
+144 – 11
C.
–144 – 11
D.
+144 + 11
1
O2(g) → CuO(s)
2
(Total 1 mark)
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3
10.
Consider the reaction between gaseous iodine and gaseous hydrogen.
I2(g) + H2(g)
2HI(g)
O
∆H = –9 kJ
Why do some collisions between iodine and hydrogen not result in the formation of the product?
A.
The I2 and H2 molecules do not have sufficient energy.
B.
The system is in equilibrium.
C.
The temperature of the system is too high.
D.
The activation energy for this reaction is very low.
(Total 1 mark)
11.
The equilibrium between nitrogen dioxide, NO2, and dinitrogen tetroxide, N2O4, is shown below.
2NO2(g)
N2O4(g)
Kc = 0.01
What happens when the volume of a mixture at equilibrium is decreased at a constant temperature?
I.
The value of Kc increases
II.
More N2O4 is formed
III.
The ratio of
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
[ NO 2 ]
decreases
[N 2 O 4 ]
(Total 1 mark)
12.
Which species could be reduced to form NO2?
A.
N2 O
B.
NO3
C.
HNO2
D.
NO
–
(Total 1 mark)
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4
13.
Which is the best definition of structural isomers?
A.
Compounds which have atoms with the same atomic numbers but different mass numbers
B.
Compounds which have the same general formula but differ by a CH 2 group
C.
Compounds which have the same empirical formula but different molecular formulas
D.
Compounds which have the same molecular formula but different arrangements of atoms
(Total 1 mark)
14.
Which experimental procedure is most likely to lead to a large systematic error?
A.
Determining the concentration of an alkali by titration with a burette
B.
Measuring the volume of a solution using a volumetric pipette
C.
Determining the enthalpy change of neutralization in a beaker
D.
Measuring the volume of a gas produced with a gas syringe
(Total 1 mark)
15.
Which of the following is consistent with Avogadro’s law?
A.
P
= constant (V, n constant)
T
B.
V
= constant (P, n constant)
T
C.
Vn = constant (P, T constant)
D.
V
= constant (P, T constant)
n
(Total 1 mark)
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5
16.
Which oxides produce an acidic solution when added to water?
I.
P4O10
II.
MgO
III.
SO3
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
(Total 1 mark)
17.
The standard enthalpy changes for the combustion of carbon and carbon monoxide are shown below.
C(s) + O2(g) → CO2(g)
CO(g) +
1
O2(g) → CO2(g)
2
O
–1
∆Hc = –394 kJmol
O
–1
ΔHc = –283 kJ mol
What is the standard enthalpy change, in kJ, for the following reaction?
C(s) +
A.
–677
B.
–111
C.
+111
D.
+677
1
O2(g) → CO(g)
2
(Total 1 mark)
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6
18.
Which of the following can increase the rate of a chemical reaction?
I.
Increasing the temperature
II.
Adding a catalyst
III.
Increasing the concentration of reactants
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
(Total 1 mark)
19.
Which statement is correct for all elements in the same period?
A.
They have the same number of electrons in the highest occupied energy level.
B.
They have the same chemical reactivity.
C.
They have the same number of occupied energy levels.
D.
They have the same number of neutrons.
(Total 1 mark)
20.
An example of a strong acid solution is perchloric acid, HClO 4, in water. Which statement is correct for
this solution?
A.
HClO4 is completely dissociated in the solution.
B.
HClO4 exists mainly as molecules in the solution.
C.
The solution reacts only with strong bases.
D.
The solution has a pH value greater than 7.
(Total 1 mark)
21.
Which are definitions of an acid according to the Brønsted-Lowry and Lewis theories?
Brønsted-Lowry theory
Lewis theory
A.
proton donor
electron pair acceptor
B.
proton acceptor
electron pair acceptor
C.
proton acceptor
electron pair donor
D.
proton donor
electron pair donor
(Total 1 mark)
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22.
Which species have the same number of electrons?
I.
2–
S
II.
–
Cl
III.
Ne
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
(Total 1 mark)
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8
23.
Magnesium is higher in the reactivity series than zinc. In the cell shown, in which direction do the
electrons flow in wire X and which metal is oxidized?
Electron flow
Oxidized
A.
Zn to Mg
Zn
B.
Mg to Zn
Zn
C.
Zn to Mg
Mg
D.
Mg to Zn
Mg
(Total 1 mark)
24.
Propene is converted to propanone in a two stage process.
Propene → X → Propanone
What is the formula of compound X?
A.
CH3CHBrCH3
B.
CH3CH2CH2Br
C.
CH3CHOHCH3
D.
CH3CH2CH2OH
(Total 1 mark)
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9
25.
What is the correct sequence for the processes occurring in a mass spectrometer?
A.
vaporization, ionization, acceleration, deflection
B.
vaporization, acceleration, ionization, deflection
C.
ionization, vaporization, acceleration, deflection
D.
ionization, vaporization, deflection, acceleration
(Total 1 mark)
26.
What is the correct sequence for the processes occurring in a mass spectrometer?
A.
vaporization, ionization, acceleration, deflection
B.
vaporization, acceleration, ionization, deflection
C.
ionization, vaporization, acceleration, deflection
D.
ionization, vaporization, deflection, acceleration
(Total 1 mark)
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10