1.
Enzymes are best described as:
A
Inorganic catalysts
B
Synthetic chemicals
C
Biological catalysts
D
Reactants
2.
Which of the following increases diffusion rate?
A
Lower temperature
B
Higher temperature
C
Higher mass
D
Lower concentration
3.
Which salt is used in photography?
A
Silver bromide
B
Sodium chloride
C
Potassium nitrate
D
Copper sulfate
4.
The scientific method mainly involves:
A
Guessing
B
Observation, hypothesis, experiment
C
Memorization
D
Storytelling
5.
Which factor has no effect on enzyme activity?
A
pH
B
Temperature
C
Substrate concentration
D
Color of enzyme
6.
Actual yield is:
A
Calculated yield
B
Maximum yield
C
Yield obtained experimentally
D
Percentage yield
7.
Alchemy contributed to chemistry by developing:
A
Scientific laws
B
Laboratory techniques
C
Atomic models
D
Chemical equations
8.
In collision theory, proper orientation means:
A
Particles must collide head-on
B
Particles must be parallel
C
Particles must collide randomly
D
Particles must have same mass
9.
A lead-acid battery is commonly used in:
A
Watches
B
Mobile phones
C
Cars
D
Torches
10.
Which process shows diffusion?
A
Rusting
B
Perfume spreading in air
C
Burning
D
Freezing
11.
A battery is made up of:
A
One cell
B
Two or more cells
C
Only electrodes
D
Only electrolyte
12.
The Contact process is used for the manufacture of:
A
Nitric acid
B
Sulphuric acid
C
Hydrochloric acid
D
Ammonia
13.
Theoretical yield is:
A
Actual amount obtained
B
Maximum possible amount
C
Minimum possible amount
D
Average yield
14.
According to Dalton, atoms are:
A
Divisible
B
Indestructible
C
Made of energy
D
Invisible waves
15.
Which salt is insoluble in water and forms precipitate?
A
Sodium sulfate
B
Ammonium nitrate
C
Barium sulfate
D
Potassium chloride
16.
Which example shows both physical and chemical change?
A
Melting ice
B
Breaking glass
C
Burning candle
D
Boiling water
17.
If actual yield is less than theoretical yield, percentage yield will be:
A
More than 100%
B
Equal to 100%
C
Less than 100%
D
Zero
18.
In the equation 2H₂ + O₂ → 2H₂O, the mole ratio of H₂ to O₂ is:
19.
Which salt is used in making soap?
A
Sodium hydroxide
B
Sodium carbonate
C
Sodium chloride
D
Calcium carbonate
20.
The unit of molarity is:
A
mol/kg
B
g/L
C
mol/L
D
g/mol