Multiple choice quiz of 20 questions. Try it as often as you like. You will get a different set of questions each time you attempt this quiz.
Which one of the following is not a physical change?
Making toast
Melting chocolate
Cutting a page in half
Mixing salt and pepper
Which one of the following is not a chemical change?
Grating cheese
Baking a cake
Rusting of a nail
Burning coal
A process that involves heat being given out, is called
an exothermic process
an endothermic process
a chemical reaction
a physical reaction
A process that involves heat being taken in is called
an endothermic process
an exothermic process
a chemical reaction
a physical change
Steam condensing on cold tiles is an example of
an exothermic process
an endothermic process
a chemical change
A student placed a thermometer in a test tube half-filled with water. She the added a spatula of ammonium chloride to the test tube and observed the temperature decrease. This is an example of
an endothermic reaction
an exothermic reaction
condensation
evaporation
Which one of the following is not true for a chemical reaction
It can easily be reversed.
A completely new substance is formed.
It involves a change in energy.
Heat is usually involved.
Rusting is a serious problem with metal structures. Which one of the following is NOT a condition necessary for rusting?
Heat
Moisture
Oxygen
In a chemical reaction, the substances that react together are called
the reactants
the products
the processes
the chemicals
The substances that are formed by the end of a chemical reaction are called
the products
the reactants
the processes
the chemicals
Photosynthesis is an important chemical reaction that takes place in plants. This process may be represented by a chemical equation. Fill in the blanks in this equation: Carbon dioxide + Water → _____________ + ___________
Glucose + Oxygen
Glucose + Air
Starch + Oxygen
Starch + Glucose
Respiration is an important chemical reaction that takes place in plants and animals. This process may be represented by a chemical equation. Fill in the blanks in this equation: Glucose + Oxygen → _______ + _________
Carbon dioxide + Water
Carbon dioxide + Air
Water + Nitrogen
Air + Water
Which French scientist showed that matter was neither created or destroyed during a chemical reaction?
Antoine Lavoisier
Marie Curie
Louis Pasteur
Pierre Curie
Fill in the blanks: _______ cannot be created or destroyed, but can be __________ from one form to another.
Matter, changed
Liquids, changed
Matter, produced
Gases, sent
Complete the following sentence: In any chemical reaction, the total mass of the reactants is always equal to the mass of the ___________.
products
processes
particles
molecules
12 grams of baking soda and 7 grams of vinegar are mixed together in a sealed container whose mass is 25 grams. After the reaction has completed, what will the combined mass of the container and products be?
44 grams
19 grams
37 grams
less tham 19 grams
There are two forms of copper sulfate. One of these looks like a powder, while the other is crystalline in appearance. What are the colours of these substances?
White powder, blue crystal
Blue powder, colourless crystal
White powder, yellow crystal
Yellow powder, blue crystal
The minimum amount of energy needed before reactants can form a product is called
activation energy
exothermic energy
reaction energy
nuclear energy
Water can be broken down into hydrogen and oxygen gases. In such a reaction, 24 cm3 of hydrogen gas is formed. What volume of oxygen gas should be formed in the same reaction?
12 cm3
24 cm3
48 cm3
18 cm3
The reaction where water is chemically broken down by passing an electric current through it, is called
electrolysis
endothermic
exothermic
electronic
In an exothermic reaction, the energy of the reactants is _________ the energy of the products.
greater than
less than
equal to
In an endothermic reaction, the energy of the reactants is _________ the energy of the products.
less than
greater than
equal to
The speed at which a reaction occurs is called its
reaction rate
velocity
activation energy
exothermic rate
The minimum energy required in order that a reaction may take place is known as
the activation energy
the reaction energy
the endothermic energy
the exothermic energy
The rate of reaction can easily be measured. Which one of the following does not measure the rate of a reaction?
Recording the colour of the reacting mixture as the reaction takes place.
Measuring the amount of one of the products present as the reaction takes place.
Measuring the amount of one of the reactants present as the reaction takes place.
Measuring the temperature of the reaction.
Which of the following factors does NOT affect the rate of a chemical reaction?
Colour of the reactants
Number of particles reacting
Temperature of the reactants
Size of the reactants
Which one of the following chemical reactions takes place at the greatest rate?
A match burning
An egg boiling
Paint drying
Cement setting
If the temperature of a reaction is decreased, what effect will this have on the reaction rate?
The rate of reaction will decrease.
The rate of reaction will increase.
It will have no effect.
The reaction will stop.
When sodium thiosulfate is added to hydrochloric acid, a slow reaction takes place in which a coloured precipitate of sulfur forms. What colour is this precipitate?
Yellow
Red
White
Green
Which one of the following factors increases the reaction rate?
More collisions between the reacting particles
Lowering the temperature of the reacting particles
Diluting the reactants
Placing the reactants in the dark
Which one of the following does heating the reactants generally NOT do to a reaction?
Slows down the speed of the particles
Increase the energy of the colliding particles
Cause more collisions
Which of the following does NOT usually happen during a chemical reaction?
There is no heat change
It is usually impossible to reverse the reaction
New substances are formed
There is usually an energy change
Peeling an apple is an example of a physical change.
TRUE
FALSE
Adding sugar to a cup of tea is a physical change because
it is possible to separate the sugar from the tea
there is no change in colour
there is no change in temperature
the tea tastes sweeter
Exothermic and endothermic reactions always involve a change in
heat
colour
volume
density
When you sweat, your body must supply heat so that the sweat evaporates. This is an example of
an endothermic reaction
an exothermic reaction
Which one of the following is an exothermic reaction?
Coal burning
An egg boiling
Water evaporating
Chocolate melting
Magnesium burns in air with a bright flame, and a white powder forms. We know that this is a chemical reaction because
a new substance is formed
you should not stare at the light
it can easily be reversed
magnesium is a metal
When performing an experiment to study the conditions necessary for rusting, some water is boiled and allowed to cool. Why is this done?
To remove oxygen that may be dissolved in the water
To purify the water
To sterilise the water
To wash the metal being tested
In an endothermic reaction, the products have _______ energy compared to the reactants.