Unit 3 Chemical Reactions Test 2023
GRADED A+ (ACTUAL TEST ) Questions and Answers (Solved)
- Type of chemical reaction that absorbs energy in order to take
place. Sign of a chemical reaction.
Answer: Endothermic
- Type of chemical reaction that releases energy as it takes place.
Sign of a chemical reaction.
Answer: Exothermic
- Solid compound produced from 2 liquids during a chemical
reaction. Sign of a chemical reaction.
Answer: Precipitate
- Gas given off during a chemical reaction; may or may not have
an odor. Sign of a chemical reaction.
Answer: Bubbles
- light, heat, color change, new substance exists
Answer: Other Signs of a Chemical Reaction
- Mass cannot be created nor destroyed; Mass can only change
forms. The total mass of products equals the total mass of the reactants.
Answer: Law of Conservation of Mass
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- Number in front of a compound's chemical formula telling you
how many molecules of that compound are needed.
Answer: Coefficient
- Number written after and BELOW an element in a chemical
formula telling you how many of the preceding element are needed for that compound or molecule.
Answer: Subscript
- Chemical equation where the total mass of the reactants equals
the total mass of the products. Produced by changing the coefficients of the com- pounds.
Answer: Balanced Equation
- Chemical change; when substances interact with each other.
Original substances are used up. New substance created.
Answer: Chemical Reaction
- Written representation of a chemical reaction/chemical change;
shows all the reactants and products. Always in the form of:
Reactants Yield (arrow) Products.
Answer: Chemical Equation
- A change that occurs when one or more substances change into
entirely new substances with different properties.
Answer: Chemical Change
- When a substance changes its phase (changes to a solid, liquid ,
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gas, or plasma) or is modified (size, shape, etc) but remains the same substance.