Which solution will change red litmus to blue?
A. HCl (aq.)
B. NaCl (aq.)
C. CH3OH (aq.)
D. NaOH(aq.)

77. Given the equation: H+ + OH- = H2O, which type of reaction does the equation represent?
A. Esterification
B. Decomposition
C. Hydrolysis
D. Neutralization

78. Which of the following elements is essential in all organic compounds?
A. Nitrogen
B. Hydrogen
C. Oxygen
D. Carbon

79. Naturally occurring polymers are
A. starch and nylon
B. starch and cellulose
C. protein and nylon
D. protein and plastic

80. Which of the following compounds is represented by the general formula CnH2n-2?
A. Butane
B. Butene
C. Butyne
D. Benzene

81. Compared to the charge and mass of a proton, an electron has
A. the same charge and a smaller mass
B. the same charge and the same mass
C. an opposite charge and a smaller mass
D. an opposite charge and the same mass

Identify the basic solution: NaOH turns red litmus paper blue.
Recognize neutralization reaction: H+ + OH- -> H2O is neutralization.
Recall essential element in organic compounds: Carbon is essential.
Identify natural polymers: Starch and cellulose are naturally occurring.
Identify alkynes: CnH2n-2 represents alkynes like butyne.
Compare electron and proton: Electron has opposite charge and smaller mass.
Final Answers: 76. D, 77. D, 78. D, 79. B, 80. C, 81. C

Explanation

Problem Analysis We will address each multiple-choice question individually, selecting the correct answer based on chemical principles.

Question 76 Solution Question 76: Red litmus paper turns blue in the presence of a base. Among the options, NaOH (sodium hydroxide) is a strong base. Therefore, the answer is D.

Question 77 Solution Question 77: The reaction H+ + OH- -> H2O represents the combination of an acid (H+) and a base (OH-) to form water, which is a neutralization reaction. Therefore, the answer is D.

Question 78 Solution Question 78: Carbon is the essential element in all organic compounds. Organic chemistry is defined by the study of carbon-containing compounds. Therefore, the answer is D.

Question 79 Solution Question 79: Naturally occurring polymers are those found in nature, such as starch and cellulose. Nylon and plastic are synthetic polymers. Therefore, the answer is B.

Question 80 Solution Question 80: The general formula CnH2n-2 represents alkynes, which contain a triple bond. Butyne is an alkyne. Therefore, the answer is C.

Question 81 Solution Question 81: Compared to a proton, an electron has an opposite (negative) charge and a much smaller mass. Therefore, the answer is C.

Final Answer Final Answers:

D

D

D

B

C

C


Examples
Understanding the properties of acids, bases, and organic compounds is crucial in many real-world applications. For example, knowing that NaOH is a strong base helps in industrial processes like soap making. Recognizing carbon as the backbone of organic molecules is essential in drug design and materials science. Identifying natural polymers like starch and cellulose is important in food science and sustainable materials development. Understanding these concepts allows us to manipulate and utilize chemical reactions and compounds for various purposes.

Answered by GinnyAnswer | 2025-07-05

The answers to the multiple-choice questions are: 76. D (NaOH), 77. D (Neutralization), 78. D (Carbon), 79. B (Starch and Cellulose), 80. C (Butyne), 81. C (Electron).
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Answered by Anonymous | 2025-07-12