Free Acids, Bases and Salts MCQs with Answers
314 Acids, Bases and Salts MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Acid and base behaviour is explained through the Bronsted-Lowry transfer of protons and the Lewis donation or acceptance of electron pairs. The topic includes pH, pOH, ionisation and water equilibrium, plus salt formation and hydrolysis, where a salt solution may become acidic, basic or neutral.
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Read the Acids, Bases and Salts notesFree MDCAT chapter notes with key terms314 questions · page 4 of 16
- A. Formic acid
- B. Oxalic acid
- C. Benzoic acid
- D. Acetic acid
Explanation: A dilute (approximately 5 percent by volume) solution of acetic acid produced by fermentation and oxidation of natural carbohydrates is…
Correct answer: Acetic acid- A. Hydrochloric Acid
- B. Nitric Acid
- C. Hydrofluoric Acid
- D. Sulphuric Acid
- E. Acetic Acid
Explanation: HF etching is capable of etching materials such as amorphous silicon dioxide; quartz and glass at very high etch rates.
Correct answer: Hydrofluoric Acid- A. It decomposes the acid
- B. It hydrolyses the acid
- C. Acid decomposes the water
- D. Acid forms hydrates with water
Explanation: Sulphuric acid is kept in air-tight bottles because if kept in the open it absorbs water vapors from the surrounding.
Correct answer: Acid forms hydrates with water- A. Yellow
- B. Pink
- C. Orange
- D. Red
Explanation: Methyl orange is orange in colour. It is used in laboratories to determine if a solution is acidic or basic.
Correct answer: Red65. Farming salt is:
- A. NaCl
- B. HF
- C. KHF2
- D. KClO3
Explanation: NaCl is an ionic compound, also known as common salt or farming salt used in cooking.
Correct answer: NaCl- A. Below 7
- B. 7
- C. Above 7
- D. At all pH
Explanation: Blue litmus paper turns red under acidic conditions (pH of below 7)
Correct answer: Below 7- A. 1
- B. 2
- C. 3
- D. 4
Explanation: Basicity means the number of replaceable hydrogen atoms. H3PO4 = 3H+ + PO4- For hydrogen to be acidic, it must be attached to a strongly…
Correct answer: 3- A. Strong acid and salt of it with a weak base
- B. Weak acid and salt of it with a strong base
- C. Strong acid and salt of it with a strong base
- D. Weak acid and salt of it with a weak base
Explanation: The formation of a buffer solution requires a weak base OR a weak acid with its salt with a strong acid OR a strong base respectively…
Correct answer: Weak acid and salt of it with a strong base- A. 7.35 to 7.45
- B. 7.55 to 7.65
- C. 7.00 to 7.25
- D. 7.85 to 7.95
Explanation: Blood is normally slightly basic, with a normal pH range of about 7.35 to 7.45. Usually, the body maintains the pH of blood close to 7.40.
Correct answer: 7.35 to 7.45- A. NH4OH + NH4Cl
- B. CH3COOH + CH3COONa
- C. C6H5COOH + C6H5COONa
- D. HCl + NaCl
Explanation: For the formation of a buffer, there should be a weak acid OR a weak base together with its salt.
Correct answer: HCl + NaCl71. The pKa value of CH3COOH is 4.74, the pH of equimolar solution of acetic acid and sodium acetate is:
- A. 13.0
- B. 7.2
- C. 4.79
- D. 4.74
Explanation: To determine the pH of an equimolar solution of acetic acid (CH3COOH) and sodium acetate (CH3COONa), we need to consider the acid-base…
Correct answer: 4.74- A. NH4+
- B. H2O
- C. H+
- D. NH3
Explanation: In the Brønsted-Lowry definition of acids and bases, a conjugate acid-base pair consists of two substances that differ only by the…
Correct answer: H2O- A. 3.0
- B. 2.7
- C. 2.0
- D. 1.5
Explanation: Given pH= 10-3 After ionization, H2SO4 ⇔ 2H+ + SO4- [H+] from H2SO4 = 2x10-3 We know that pH = -log10 [H+] pH = -log10 (2 x 10-3) = 3 -…
Correct answer: 2.7- A. CH3COOH > HF > H2SO4 > HCI
- B. HCI > H2SO4 > HF > CH3COOH
- C. HCl > CH3COOH > HF > H2SO4
- D. HCl > HF > H2SO4 > CH3COOH
Explanation: Ka is a measure of ionization of the acid, thereby a greater Ka corresponds to greater acidic strength.
Correct answer: HCI > H2SO4 > HF > CH3COOH- A. An acid
- B. A base
- C. An amphoteric species
- D. A salt
Explanation: Water is an example of an amphiprotic substance. This means it is able to donate a proton or accept a proton.
Correct answer: An amphoteric species- A. Weak
- B. Strong
- C. Unstable
- D. None of these options
Explanation: Weak acids have strong bonds to their H+. Strong acids have weak bonds to their H+.
Correct answer: Strong- A. Ethane
- B. Ethyl Chloride
- C. Ethanol
- D. Phenol
Explanation: Phenols are much more acidic than alcohols because the negative charge in the phenoxide ion is not localized on the oxygen atom, as it is…
Correct answer: Phenol- A. 11
- B. 6
- C. 3
- D. 10
Explanation: In order to calculate this pH, we assume that all of Mg(OH)2 dissociates in solution.
Correct answer: 11- A. pH is not affected by time
- B. All of these
- C. Have definite pH
- D. pH is not affected by dilution
Explanation: Buffers are solutions that resist the change in pH when a small amount of acid or base is added to them.
Correct answer: All of these- A. Titration with KMnO4
- B. Titration with standard alkali
- C. Distillation
- D. Evaporation of mixture
Explanation: The change in the concentration of acid at different intervals after the hydrolysis of ester is calculated by titration with standard…
Correct answer: Titration with standard alkali