pH
What is the pH of a neutral substance?
A. 0
B. 3
C. 7
D. 14
C: pH 7
What does an indicator do?
A. Changes colour depending on pH
B. Makes chemicals hotter
C. Changes the size of chemicals
D. Makes chemicals disappear
A. Changes colour depending on pH
Which is a physical change?
A. Burning wood
B. Melting ice
C. Rusting iron
D. Cooking an egg
B. Melting ice
Which is a chemical change?
A. Melting ice
B. Cutting paper
C. Burning wood
D. Freezing water
C. Burning wood
Which substance is usually acidic?
A. Lemon juice
B. Water
C. Baking soda solution
D. Soap
A. Lemon juice
A substance with a pH of 3 is:
A. Acidic
B. Neutral
C. Basic
D. A gas
A. Acidic
Universal indicator turns green.
The substance is probably:
A. Acidic
B. Neutral
C. Basic
D. A gas
B. Neutral
Which is a physical change?
A. Tearing paper
B. Burning paper
C. Rusting metal
D. Cooking food
A. Tearing paper
Which can be evidence of a chemical reaction?
A. Bubbles or gas
B. Cutting something
C. Changing shape
D. Breaking an object
A. Bubbles or gas
Which substance is usually neutral?
A. Vinegar
B. Pure water
C. Lemon juice
D. Baking soda solution
B. Pure water
Which pH represents a base?
A. 2
B. 5
C. 7
D. 11
D. 11
Universal indicator turns red.
The substance is probably:
A. Acidic
B. Neutral
C. Basic
D. Frozen
A. Acidic
Why is melting ice a physical change?
A. A new substance is made
B. Gas is produced
C. No new substance is made
D. Light is produced
C. No new substance is made
Vinegar and baking soda are mixed and bubbles form.
This is:
A. A physical change
B. A chemical change
C. No change
D. Melting
B. A chemical change
Which substance is most likely a base?
A. Vinegar
B. Lemon juice
C. Baking soda solution
D. Orange juice
C. Baking soda solution
Which statement is correct?
A. pH 2 is more acidic than pH 6
B. pH 7 is strongly acidic
C. pH 12 is an acid
D. pH 5 is a base
A. pH 2 is more acidic than pH 6
Universal indicator turns blue or purple.
The substance is probably:
A. Acidic
B. Neutral
C. Basic
D. Water
C. Basic
Which is NOT a physical change?
A. Crushing chalk
B. Freezing water
C. Cutting paper
D. Burning wood
D. Burning wood
What is the main difference between a physical and chemical change?
A. Chemical changes produce new substances
B. Physical changes always produce bubbles
C. Chemical changes only happen when heated
D. Physical changes always change colour
A. Chemical changes produce new substances
Which statement about bases is correct?
A. Bases have a pH below 7
B. Bases have a pH above 7
C. Bases always have a pH of 7
D. Bases are always red
B. Bases have a pH above 7
A mystery solution has a pH of 11. What can you conclude?
A. It is acidic
B. It is neutral
C. It is basic
D. It must be water
C. It is basic
Why are indicators useful?
A. They allow us to taste chemicals safely
B. They help us identify the pH of substances
C. They make every chemical reaction happen faster
D. They turn every chemical blue
B. They help us identify the pH of substances
A student crushes a sugar cube into powder. Why is this a physical change?
A. Sugar becomes a new substance
B. Only its size and shape change
C. Gas is produced
D. Its chemical composition changes
B. Only its size and shape change
A student notices bubbles, a temperature change and a new smell.
What is the best conclusion?
A. Only a physical change occurred
B. A chemical reaction probably occurred
C. Nothing happened
D. The substance only melted
B. A chemical reaction probably occurred
A mystery solution has a pH of 11. What is it most likely?
A. Strongly acidic
B. Weakly acidic
C. Neutral
D. Basic
D. Basic