1.
Melting of ice is a:
A
Exothermic process
B
Endothermic process
C
Chemical reaction
D
Combustion
2.
In an endothermic reaction, ΔH is:
A
Negative
B
Positive
C
Zero
D
Constant
3.
Oliver is studying the enthalpy of combustion. He knows that the enthalpy of combustion of methane is -890 kJ/mol. What does this indicate?
A
The reaction absorbs 890 kJ of heat
B
The reaction releases 890 kJ of heat per mole of methane
C
The reaction has no heat change
D
The reaction requires 890 kJ of activation energy
4.
Julia is studying the prevention of corrosion by coating with a thin layer of another metal. She learns that tinning is used to coat steel with tin. What is the main application of tinned steel?
A
In aircraft manufacturing
B
In food cans
C
In car bodies
D
In electrical wiring
5.
Which reaction shows reduction?
A
Fe → Fe2+ + 2e−
B
Cl− → Cl + e−
C
Cu2+ + 2e− → Cu
D
Zn → Zn2+ + 2e−
6.
Which process requires activation energy?
A
All chemical reactions
B
Only exothermic reactions
C
Only endothermic reactions
D
Only physical changes
7.
Lead-acid battery is used in:
A
Mobile phones
B
Wrist watches
C
Cars
D
Calculators
8.
What happens to surroundings in an exothermic reaction?
A
They cool down
B
They gain heat
C
No change
D
They lose mass
9.
Fatima is studying oxidation states. She learns that oxidation state is the charge an atom would have if all bonds were ionic. What is the oxidation state of oxygen in most compounds?
10.
Hina is learning about redox in photography. She learns that the photographic process uses silver halides. What happens to the silver ions during the development of a photograph?
A
They are oxidized to silver metal
B
They are reduced to silver metal
C
They are dissolved in water
D
They are converted to silver nitrate
11.
Omar is learning about oxidation states. He knows that the oxidation state of hydrogen is usually +1, except in metal hydrides where it is -1. In NaH, what is the oxidation state of hydrogen?
12.
Electroplating is used to:
A
Remove rust
B
Protect metals and improve appearance
C
Increase corrosion
D
Purify metals
13.
Chloe is studying redox reactions in terms of transfer of hydrogen. She learns that oxidation involves loss of hydrogen while reduction involves gain of hydrogen. In the reaction: H2S + Cl2 → 2HCl + S, which substance is oxidized?
14.
A dry cell is commonly used in:
A
Cars
B
Torch and clocks
C
Electroplating
D
Industrial furnaces
15.
Aisha is studying oxidation states of polyatomic ions. She learns that the sum of oxidation states in an ion equals the ion's charge. In the nitrate ion (NO3^-), what is the oxidation state of nitrogen if oxygen is -2?
16.
The electrolyte in an electrochemical cell is:
A
A metal
B
A conductor of electrons
C
A solution that conducts ions
D
An insulator
17.
Which energy change is shown by ΔH > 0?
A
Exothermic
B
Endothermic
C
Neutral
D
Spontaneous
18.
Corrosion is an undesirable process because it:
A
Improves metal quality
B
Increases conductivity
C
Damages metals
D
Prevents oxidation
19.
Waleed is determining the oxidation number of an atom in a compound. He wants to find the oxidation state of chromium in K2Cr2O7. Given K is +1 and O is -2, what is the oxidation state of Cr?
20.
Sacrificial protection uses:
A
More reactive metal
B
Less reactive metal
C
Same metal
D
Non-metal
21.
Energy absorbed during bond breaking is:
A
Released
B
Ignored
C
Stored
D
Required
22.
Energy released during bond formation is:
A
Absorbed
B
Released
C
Lost
D
Stored
23.
Oliver is studying the effect of catalysts. He knows that catalysts are used in many industrial processes. Which of the following is a characteristic of a catalyst?
A
It is consumed in the reaction
B
It changes the enthalpy of reaction
C
It is chemically unchanged at the end of the reaction
D
It stops the reaction from occurring
24.
Tina is learning about redox reactions in photography. She understands that the developer reduces silver halide to silver. What is the role of the developer in the photographic process?
A
It oxidizes the silver halide
B
It is a reducing agent
C
It is an oxidizing agent
D
It dissolves the silver halide
25.
Which reaction absorbs heat from surroundings?
A
Combustion
B
Neutralization
C
Endothermic
D
Oxidation
26.
Which symbol is used for enthalpy?
27.
Vera is studying oxidation states. She learns that the oxidation state of fluorine is always -1 in all its compounds. What is the oxidation state of fluorine in F2?
28.
David is studying thermochemistry. He knows that thermochemistry is the study of heat changes in chemical reactions. What is the heat change at constant pressure called?
A
Internal energy
B
Enthalpy
C
Entropy
D
Free energy
29.
Qasim is learning about oxidizing and reducing agents. He understands that a substance that causes oxidation is an oxidizing agent. In the reaction: 2Mg + O2 → 2MgO, what is the oxidizing agent?
A
Mg
B
O2
C
MgO
D
Both A and B
30.
Zayn is learning about redox reactions. He understands that a redox reaction involves the transfer of electrons. Which of the following is a redox reaction involving transfer of electrons?
A
Na + Cl → NaCl
B
NaCl → Na+ + Cl-
C
Na+ + Cl- → NaCl
D
None of the above