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WorksheetsChemical Reactions
Total questions: 25
Worksheet time: 25mins
What is a chemical reaction?
a change in matter when the molecules rearrange to make new molecules
a change in matter when matter changes its form or appearance
a change in matter when the physical appearance changes
a very boring change in matter
The reactants in the image above are:
CH4 and 2 O2
2 H2O and CO2
All of these are reactants
All of these are products
The products in the image above are:
CH4 and 2 O2
2 H2O and CO2
All of these are reactants
All of these are products
When energy like heat and light are given off in a chemical reaction it is called
exothermic
endothermic
eccentric
ectomorphic
Identify the products and reactants
reactants
products
Identify which are the products and reactants
products
reactants
Which of the following is a type of chemical reaction?
Melting
Combustion
Freezing
Evaporation
Label the parts of the reaction.
Reactants
Products
What type of reaction involves the breaking down of a substance into simpler substances?
Single Displacement Reaction
Double Displacement Reaction
Synthesis Reaction
Decomposition Reaction
What is the main characteristic of a combustion reaction?
It involves the formation of a precipitate
It involves the release of energy in the form of heat and light
It involves the absorption of energy
It involves the formation of a gas
A copper penny turning greenish after a few years is an example of ...
Chemical Change
Physical Change
When energy is absorbed and taken in during a chemical reaction it is called
exothermic
endothermic
eccentric
ectomorphic
When the matter in a chemical reaction gets colder it is called
exothermic
endothermic
eccentric
endomorphic
When the matter in a chemical reaction gets warmer it is called
exothermic
endothermic
eccentric
endomorphic
Which is the correct description of photosynthesis
Photosynthesis is a chemical reaction because the atoms of the molecules get rearranged to form new molecules
Photosynthesis is a chemical reaction because the molecules stay the same before and after the change
Photosynthesis is a physical change because nature makes it happen
Photosynthesis is a physical change because the atoms stay the same
You know that a chemical reaction is occurring here because you see __________________ . (Pick 3)
purple color
smoke
ice formation
fire
a yellow precipitate
When zinc reacted with hydrochloric acid, what was the result of this reaction?
a white powder
a blue liquid
a brown precipitate
a gas
We know that there was a chemical reaction occurring when 2 clear liquids were mixed together. That is because we show the production of a _____________.
solid.
precipitate.
gas.
A precipitate is a ___________ that forms when 2 liquids react together.
solid
liquid
gas
plasma
The result of the experiment between Iodine and Aluminum was the production of __________________.
clear liquid.
a white powder.
yellow precipitate.
bubbles.
How is a chemical change different from a physical change?
there is no difference
a physical change creates a new substance
a chemical change creates a new substance
Consider burning a hot cheeto. This is a chemical reaction. The hot cheeto, flame, and oxygen in the air enter a chemical reaction and produce ash and some other things. Considere quemar un cheeto caliente. Ésta es una reacción química. El cheeto caliente, la llama y el oxígeno del aire entran en una reacción química y producen cenizas y algunas otras cosas. Which statement would be true?
Ash is a different substance than the hot cheeto.
The atoms of wood and oxygen disappear during the burning.
Ash has similar properties to oxygen.
The atoms of the ash did not exist before.
What is the law of conservation of mass in chemical reactions?
Mass is created during a chemical reaction
Mass is destroyed during a chemical reaction
Mass is neither created nor destroyed during a chemical reaction
Mass is converted into energy during a chemical reaction
Which of the following is an example of a synthesis reaction?
@@ ext{NaCl} ightarrow ext{Na} + ext{Cl}_2@@
@@ ext{H}_2 + ext{O}_2 ightarrow ext{H}_2 ext{O}@@
@@ ext{C}_6 ext{H}_{12} ext{O}_6 ightarrow ext{C}_2 ext{H}_5 ext{OH} + ext{CO}_2@@
@@ ext{AgNO}_3 + ext{NaCl} ightarrow ext{AgCl} + ext{NaNO}_3@@
In a chemical reaction, what does the term 'activation energy' refer to?
The energy released during the reaction
The energy required to start the reaction
The energy absorbed by the reactants
The energy stored in the products
