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WorksheetsQuiz on Chemical and Physical Changes
Total questions: 35
Worksheet time: 37mins
The chart shows how materials can change chemically. Why are these changes classified as chemical changes?
New substances formed
Materials take different shapes
Temperature affects the objects
Some energy is absorbed
When baking soda reacts with vinegar, bubbles form and the container feels cold. This is an example of:
Exothermic reaction - energy is released.
Endothermic reaction - energy is absorbed from the surroundings.
Neither endothermic nor exothermic - no energy transfer occurs.
The coldness is due to the vinegar, not the reaction itself.
A partial periodic table is shown below. Use the periodic table to predict if an ionic or covalent bond forms. (Hint: How do we know if it is ionic or covalent?) Example NaCl-What is the bond, how do you know?
How many different elements are involved in the chemical reaction shown below? Ca + 2H₂O → Ca(OH)₂ + H₂
(a)
The formation of an ionic bond involves the
transfer of electrons.
sharing of neutrons.
transfer of neutrons.
sharing of protons.
The formation of a covalent bond involves the
transfer of electrons.
sharing of electrons.
transfer of neutrons.
sharing of protons.
Which type of matter can be separated by physical means?
atom
element
compound
mixture
The chart below lists samples of three materials. Classify each sample in the chart as an element, a compound, or a mixture by typing on the line.
(a)
The equation below shows the products formed with a solution of silver nitrate (AgNO₃) reacts with a solution of sodium chloride (NaCl). AgNO₃ + NaCl → NaNO₃ + AgCl (Reactants) ⇒ (Products) In this equation, the total mass of the reactants is
greater than the total mass of the products
equal to the total mass of the products
equal to the mass of AgCl
less than the mass of AgCl
The diagram below represents two atoms in a molecule of oxygen that combine chemically with one atom of carbon to form a carbon dioxide molecule.
a mixture
an element
a solution
a compound
Which property of water allows it to dissolve many different substances?
It is a polar molecule.
It contains hydrogen atoms.
It has a high melting point.
It has a low density.
When calcium carbonate (CaCO₃) is heated, it decomposes to form calcium oxide (CaO) and carbon dioxide (CO₂). The equation below shows this reaction. CaCO₃ → CaO + CO₂ (Reactants) → (Products) In this reaction, the total mass of CaCO₃
is less than the mass of CaO plus the mass of CO₂
is greater than the mass of CaO plus the mass of CO₂
equals the mass of CaO plus the mass of CO₂
equals the mass of CaO minus the mass of CO₂
Identify the number of atoms of each element that comprises the compound below.
C₆H₁₂O₆
C has ___ atoms
H has ___ atoms
O has ___ atoms
(a)
Balance the following equation by adding the appropriate coefficient in the appropriate blanks. If there is no coefficient needed, put 1 to indicate there is only 1 molecule of that substance.
(a)
Which of the following shows an exothermic reaction?
2H₂ + O₂ → 2H₂O
2Na + Cl₂ → 2NaCl + energy
2H₂O + energy → 2H₂ + O₂
6CO₂ + 6H₂O + energy → C₆H₁₂O₆ + 6O₂
If 100 grams of vinegar and 5 grams of baking soda are poured in a container, a small amount of gas will be produced. What will the final mass of the products be if the gas is trapped in the container?
100 grams
104 grams
105 grams
110 grams
A student has a mixture of sugar and water. What is the best method for the student to use to separate the sugar from the water?
filtration
evaporation
magnetism
pouring off the water from the mixture
Many people use a propane gas stove to cook when camping. When propane gas burns, a chemical reaction occurs. In this chemical reaction, propane will react with oxygen to form carbon dioxide and water. Use the model and what you know about chemical reactions to answer the questions below. Support your answers using the model to describe what occurs with the atoms that make up propane, oxygen, carbon dioxide, and water. Be sure to include the number and/or types of atoms for each molecule before and after the reaction. How does the model show that the mass is conserved during the reaction?
A student is comparing four elements on the periodic table. The elements are labeled in the image. Select the two elements that have properties that are the MOST similar.
A and B
A and D
A and C
B and C
B and D
Identify the number of atoms of each element shown in the chemical formula below. Al(NO₃)₃
(a)
When a chlorine atom gains an electron, it becomes
a negative ion
a positive ion
a neutral atom
a charged compound
The image below shows the first two columns of the periodic table.
K, Ca, Sr
K, Cs, Fr
K, Ca, Rb
K, Sr, Li
Student 1 claims that whenever the color of a substance changes, a chemical change has occurred. Student 2 claims that food coloring can change the color of a substance without causing a chemical change. To test their claims, the students add red food coloring to a glass of water. The students observe that the clear water turns a light pink color. Their teacher then runs a test to show that the pink solution contains both water molecules and food-coloring molecules. Based on these findings, which student is correct?
Student 1, because the food-coloring molecules were found in the pink solution
Student 1, because the state of matter changed when the food coloring was added
Student 2, because no new substance was formed when there was a color change
Student 2, because the red food coloring caused the water to change to a pink color
An experiment was conducted to observe the effects of acid rain on building materials such as limestone, often used for statues and monuments. Three pieces of limestone were carved with the same pattern and placed in tubes A, B, and C. Tube A contains water only. Tube B contains water and carbon dioxide from the student blowing into the water through a straw. Tube C contains vinegar (to simulate acid rain). The next day, the student observed and recorded the results in the data table below. Observations of Limestone in Test Tubes A, B, and C Test Tube A: no change observed in the limestone Test Tube B: limestone slightly smaller and carvings reduced Test Tube C: limestone much smaller and carvings no longer visible Based on the results of the experiment, what effect can acid rain have on statues and monuments?
Acid rain can physically weather a statue or monument
Acid rain can chemically weather a statue or monument
Acid rain makes monuments invisible
Acid rain has no effect on statues or monuments
Surface tension is the property of the surface of a liquid that allows it to resist external forces by sticking together. This property is due to the (a) nature of water molecules.
A mountain showed the following change in profile over millions of years. What happened to most of the material removed from the mountain?
The material weathered to form new sediments.
The material was absorbed by plant roots.
The material disintegrated from exposure to sunlight.
The material was destroyed by chemical reactions.
In a climate with cold winters, a rock cracks and breaks. What substance froze inside the rock causing it to break?
calcium
oil
oxygen
water
What property of water is demonstrated in the picture?
adhesion
cohesion
thermal energy
physical weathering
Label the parts of the reaction.
Reactants
Products
Identify which are the products and reactants
The quantity of matter present in an object is called
weight
Gram
mass
density
What is a sample of matter that has the same chemical composition throughout called?
Mixture
Compound
Element
Pure Substance
Which statement describes a chemical property of copper?
Copper has a red-orange color.
Copper can be flattened into sheets.
Copper reacts with oxygen.
Copper conducts an electric current.
Which of the following is an example of a chemical property?
Density
Color
Malleability
Paper's ability to burn
Which of the following is a chemical property of water?
Reacts with pure sodium
Boils at 100 oC
Is liquid at room temperature
Has a density of 1 gm/mL
