Matter & Mixtures
1. Which of the following is a pure substance?
A) Saltwater
B) Air
C) Oxygen gas (O₂)
D) Milk
Oxygen Gas
In this reaction: Cu²⁺ + Fe → Cu + Fe²⁺, what happens to the Cu atoms?
A) Lose electrons
B) Gain electrons
C) Remain unchanged
D) React with oxygen
Gain electrons
Which gas is primarily consumed during car engine combustion?
A) Carbon dioxide
B) Nitrogen
C) Hydrogen
D) Oxygen
Oxygen
What is the chemical symbol for potassium?
A) P
B) K
C) Po
D) Pt
K
What is the molar mass of H₂O?
A) 10 g/mol
B) 18 g/mol
C) 16 g/mol
D) 2 g/mol
18 g/mol
What is the most abundant gas in Earth’s atmosphere?
A) Oxygen
B) Carbon dioxide
C) Nitrogen
D) Hydrogen
Nitrogen
Which of the following is a decomposition reaction
A) Na + Cl₂ → NaCl
B) HCl + NaOH → NaCl + H₂O
C) 2H₂O₂ → 2H₂O + O₂
D) Cu + AgNO₃ → Cu(NO₃)₂ + Ag
C) 2H₂O₂ → 2H₂O + O₂
Which statement is true about elements?
A) They can be broken down into simpler substances by physical means
B) They are composed of only one kind of atom
C) They are mixtures of atoms and molecules
D) They always exist as gases
They are only composed of one kind of atom
What is the coefficient for O₃ in the balanced equation 3O₂ → ___O₃?
A) 1
B) 2
C) 3
D) 4
2
What is a mole in chemistry?
A) A unit of mass
B) A unit for volume
C) 6.02 × 10²³ particles of a substance
D) The amount of a substance in a solution
C) 6.02 x 10 ^ 23 particles of a substance
Which of the following is a chemical change?
A) Frying an egg
B) Freezing water
C) Dissolving sugar in water
D) Boiling alcohol
Frying an egg
The type of energy involved in motion is best classified as:
A) Potential energy
B) Kinetic energy
C) Chemical energy
D) Thermal energy
Kinetic energy
How many electrons does a Fe³⁺ ion have?
A) 26
B) 23
C) 29
D) 3
23
In a chemical equation, what does (aq) indicate?
A) Aqueous gas
B) A solid in water
C) A compound with acid properties
D) Dissolved in water
Dissolved in water
If 2H₂ + O₂ → 2H₂O, how many moles of water are produced from 4 moles of hydrogen gas?
A) 2
B) 4
C) 6
D) 8
B) 4
Helium (He) is a _______ at room temperature.
A) Gas
B) Liquid
C) Solid
D) Plasma
Gas
What is conserved in a balanced chemical equation?
A) Number of molecules
B) Number of atoms
C) Volume of substances
D) Temperature
Number of Atoms
What is the number of neutrons in the isotope ⁸⁰Br?
A) 35
B) 45
C) 80
D) 115
45
What is the monomer of polypropylene?
A) CH₂=CH–CH₃
B) C₂H₄
C) CH₄
D) CH₂=CH₂
CH₂=CH–CH₃
n the balanced equation C₈H₈ + ___O₂ → 8CO₂ + 4H₂O, what is the coefficient for O₂?
A) 8
B) 16
C) 4
D) 32
16
When water is put in the freezer and solidifies into ice cubes:
A) Heat is absorbed by the water
B) The temperature of the water increases
C) Heat has been given off by the water
D) The water evaporates
Heat has been given off by the water
Burning 1 mole of methane in oxygen releases 803 kJ. How much energy is released by burning 4 moles?
A) 803 kJ
B) 200 kJ
C) 1606 kJ
D) 3212 kJ
3213 kJ or 3212 kJ
Which two subatomic particles have approximately the same mass?
A) Electrons and protons
B) Neutrons and electrons
C) Protons and neutrons
D) Neutrons and nucleus
Protons and Neutrons
The sharing of valence electrons between two atoms is known as:
A) Covalent bonds.
B) Ionic bonds
C) Metallic bonds
D) Hydrogen bonds
Covalent bonds
What does the coefficient in a chemical equation tell you?
A) The number of atoms in one molecule
B) The number of moles involved in the reaction
C) The amount of heat released
D) The molarity of the solution
B) The number of moles involved in the reaction