WorksheetsChemistry Unit Test
Total questions: 20
Worksheet time: 42mins
In a chemical reaction, no new atoms are created, and no atoms are destroyed.
How many Carbons are present on the reactant side?
1
2
3
4
How many Hydrogens are on the product side of this chemical equation?
1
2
3
4
How many Oxygens are on the product side of this chemical equation?
1
2
3
4
Why are chemical equations always balanced? Select ALL that apply.
Matter cannot be created.
Matter cannot be destroyed.
Matter can only be rearranged/conserved.
Matter doesn't matter.
Is this chemical equation balanced? Why or why not? Choose the BEST answer.
Yes, the amount of atoms for each element are equal on both the reactant and product side.
No, the carbons are not the same number on both the reactant and product side.
No, neither the carbons or hydrogens are the same amount on both the reactant and product side.
No, none of the elements (carbon, hydrogen, or oxygen) are the same amount on both the reactant and product side.
Which of the following 2 are chemical reactions?
sugar dissolving in water
water turning into steam
burning wood
mixing baking soda and vinegar
tearing paper
When coal burns carbon dioxide is produced from the carbon in coal and the oxygen in air. Which of these is the best evidence that a chemical reaction occurs when coal burns?
The shape of the coal changes
Oxygen is present
A new substance is produced
Coal is made up of more than one element
All of the following are indicators of a chemical reaction except one. Which one is NOT an indicator that a chemical reaction has taken place?
the production of heat or light
a color change
the production of gas bubbles
the dissolving of one substance in another
A student places a piece of a potato into a container of hydrogen peroxide and observes bubbles forming around the potato. The presence of bubbles might indicate the formation of a new substance because bubbles -
could show that a gas is forming
always rise to the top of a liquid.
are almost always perfectly spherical.
usually burst after a few minutes.
Hydrogen peroxide breaks down to form water and oxygen gas. A thermometer indicates an increase in temperature. Which observation is evidence that a chemical reaction has occurred?
The mass of the solution remains the same.
Phase changes are observed.
The color of the solution remains clear.
The temperature of the solution increases.
