71. What is the chemical formula of sulfuric acid?

A) H2SO3
B) H2SO4
C) H2S
D) H2O
Answer: B) H2SO4

72. Which of the following is the correct Lewis structure for water?

A) H-O-H
B) H=O=H
C) H-O-H with two lone pairs on Oxygen
D) H-O-H with one lone pair on Oxygen
Answer: C) H-O-H with two lone pairs on Oxygen

73. Which gas is released during photosynthesis?

A) Oxygen
B) Carbon Dioxide
C) Nitrogen
D) Hydrogen
Answer: A) Oxygen

74. Which of the following is the most abundant element in the human body?

A) Carbon
B) Oxygen
C) Hydrogen
D) Nitrogen
Answer: B) Oxygen

75. Which of the following is a macromolecule?

A) Water
B) Salt
C) Protein
D) Oxygen
Answer: C) Protein

76. Which of the following metals reacts with water to produce hydrogen gas?

A) Copper
B) Silver
C) Sodium
D) Iron
Answer: C) Sodium

77. What is the main constituent of air?

A) Oxygen
B) Nitrogen
C) Carbon Dioxide
D) Argon
Answer: B) Nitrogen

78. Which of the following is the formula for baking soda?

A) NaCl
B) NaHCO3
C) K2CO3
D) CaCO3
Answer: B) NaHCO3

79. Which of the following compounds contains ionic bonds?

A) H2O
B) CO2
C) NaCl
D) CH4
Answer: C) NaCl

80. Which of the following processes is endothermic?

A) Combustion of gasoline
B) Freezing of water
C) Melting of ice
D) Respiration
Answer: C) Melting of ice