Chemistry revision Flashcards
(26 cards)
What does the hazard symbol with a flame represent?
Flammable materials
True or False: The biohazard symbol indicates biological substances that pose a threat to the health of living organisms.
True
Fill in the blank: The pH scale ranges from ___ to ___.
0 to 14
What pH value indicates a neutral solution?
7
Which indicator turns red in acidic solutions?
Litmus paper
What is a chemical change?
A change that results in the formation of new chemical substances.
True or False: Physical changes alter the chemical composition of a substance.
False
What hazard symbol indicates a corrosive substance?
A symbol with a test tube pouring onto skin and materials.
Which of the following is a physical change? A) Burning wood B) Dissolving sugar in water
B) Dissolving sugar in water
What does the skull and crossbones hazard symbol signify?
Toxic or fatal substances
What is the effect of an acid on litmus paper?
It turns blue litmus paper red.
What is the pH of a strong acid?
Less than 3
Fill in the blank: A solution with a pH value of 10 is considered ___.
Basic
What type of change is rusting of iron?
Chemical change
True or False: Indicators can show the pH of a solution.
True
What is the pH of pure water?
7
What hazard symbol indicates a substance that may cause environmental damage?
A fish and tree symbol.
Which of the following is NOT a characteristic of a chemical change? A) Color change B) Formation of gas C) Change in state
C) Change in state
What is the primary use of the pH scale in chemistry?
To measure the acidity or basicity of a solution.
Fill in the blank: A substance with a pH of 4 is considered to be ___ compared to a substance with a pH of 8.
More acidic
What does a pH indicator change from red to blue signify?
A transition from acidic to basic.
What hazard symbol represents an explosive substance?
A symbol with an exploding bomb.
True or False: The pH scale is logarithmic.
True
What is an example of a physical change?
Melting ice
