AnswersSVHS Chemistry 1 FAMolecular Geometry

Evidence of Chemical Reactions Answers

0 verified answers1 views
1
Free Preview

The images show two processes. Image A: a roasting marshmallow Image B: melting iceWhich statement about the two images is true?

Question illustration
A
Image A shows a physical change, and image B shows a chemical reaction.
B
Image A shows a chemical reaction, and image B shows a physical change.
C
Both images show chemical reactions that are endothermic.
D
Both images show chemical reactions that are exothermic.
2
Free Preview

A piece of limestone erodes due to acid rain. This process can be best described as a

A
slow chemical change.
B
rapid chemical change.
C
slow physical change.
D
rapid physical change.
3

Which is the most important question for deciding if a chemical reaction has occurred?

A
Was there a change in the size?
B
Was any heat energy given off?
C
What is the density of the substance?
D
What is the texture of the substance?
4

Which statement about a chemical reaction is true?

A
It occurs only at low temperatures.
B
It occurs only at high temperatures.
C
It occurs whenever a physical change takes place.
D
It occurs whenever a chemical change takes place.
5

During an experiment, Mr. Lehman tells his students to be alert for signs that an endothermic reaction is happening. Which of the following scenarios would his students most likely observe?

A
A test tube becomes cool to the touch.
B
A liquid appears to glow.
C
A new odor comes from a beaker.
D
A solid forms from a mixture of solutions.
6

A solid is placed in a solution. Which observation most likely indicates that a chemical reaction has occurred?

A
The size of the solid has rapidly decreased.
B
The color of the solution has not changed.
C
The solid has bubbles forming on its surface.
D
The temperature of the solution stays the same.
7

Which term best describes the role of hydrogen gas in the formation of a water molecule?

A
catalyst
B
inhibitor
C
product
D
reactant
8

Which statement describes a chemical reaction?

A
Atoms in the products are rearranged to form new substances.
B
Atoms in the reactants are rearranged to form new substances.
C
Atoms in the products change into new atoms to form new substances.
D
Atoms in the reactants change into new atoms to form new substances.
9

When sodium metal is added to water, an orange flame is observed on the metal surface. Based on this observation, what can best be concluded?

A
A physical change occurs because the metal gets smaller.
B
A chemical reaction occurs because the liquid becomes cloudy.
C
A chemical reaction occurs because heat and light are given off.
D
A physical change occurs because vapor is released into the air.
10

Two different liquids are mixed together. Which observation indicates that an exothermic chemical reaction has taken place?

A
an increase in volume
B
a decrease in volume
C
a rise in temperature
D
a drop in temperature

Did you find these answers helpful?

More from this Course

Instruction
4 verified answers

Instruction

Assignment
4 verified answers

Assignment

Assignment
2 verified answers

Warm-Up