MCQs on pH Scale and Buffer Solution

The amount of hydrogen ions in the water has a big impact on the growth of bacteria. This concentration is usually written in terms of pH, which is the logarithm of the reciprocal of the hydrogen ion. This is how this is usually written. There is another way to talk about hydrogen ion concentration, and it’s called pH. Buffered solution is a solution that doesn’t change its pH even after strong acids or bases are added to it. It also doesn’t change when the solution is made up of water. buffer solutions become very useful when the concentration of the conjugate acid-base pair is higher, which makes them more useful. The pH scale shows how strong acids and alkalis can be at different points on the scale. To measure how strong something is, look at this scale. The most acidic thing is 0 on this scale. Each number on the pH scale has a different colour when it’s lit up by the universal indicator, so it looks different.

1. Range of pH scale is

1. 1. 7 to 10
   2. 0 to 10
   3. 0 to 14
   4. 7 to 14

Answer: (C)

The pH scale spans from 0 (very acidic) to 14 (extremely basic) (highly alkaline). A neutral solution has a pH value of seven. On the pH scale, an acidic solution is indicated by a number less than 7. While a basic solution is represented by a pH value more than 7, an acidic solution is represented by a number less than 7.

2. Level of pH found in antacid solution

1. 1. ≤ 6.5
   2. ≥ 7.0
   3. > 10
   4. > 14

Answer: (B)

Antacids are weak bases that work by neutralising the acid produced by the stomach. Raising the pH of the stomach contents has the effect of suppressing the action of pepsin, which exacerbates ulcers caused by acid reflux disease. Antacids are efficient at relieving stomach discomfort because, when they react with acids, they produce a pH that is close to neutral. The pH value of stomach acid is 1, while the pH value of an antacid tablet is 10. As a result of mixing them together, the pH is closer to 7, which is considered neutral.

3. Three unknown solutions are given with pH value of 6, 8 & 9.5 respectively. Which solution will contain the maximum OH– ion?

1. 1. Solution sample-1
   2. Solution sample-2
   3. Solution sample-3
   4. Data are insufficient

Answer: (C)

Bases have a proclivity to release the OH ion, and bases have a pH greater than 7 compared to acids. As the pH of the solution rises, the likelihood of the release of OH ion rises as well. The pH of a particular solution is determined by the amount of ion present in the solution at any given time. It is the pH of a solution that determines whether the solution is acidic or basic. If the pH of a solution is more than 7, the solution is considered basic. If the pH of a solution is less than 7, the solution is acidic, and if the pH of a solution is greater than 7, the solution is neutral.

4. pH of neutral salt is

1. 1. 7
   2. <7
   3. >7
   4. 0

Answer: (A)

All ph values below neutral are considered acidic, whilst all ph levels over 7.0 are considered alkaline. These ions do not interact with either the hydrogen or the hydroxide ions in the environment. The pH of salt is usually around seven. Normally, salts formed by strong acids and strong bases do not hydrolyze; hence, no reaction occurs between the ions and water, and the solution remains neutral with a pH of seven.

5. Ammonium sulphate salt is

1. 1. basic salt
   2. acidic salt
   3. neutral salt
   4. complex salt

Answer: (A)

The reaction between the sulphuric acid and the ammonium hydroxide results in the formation of ammonium sulphate. Acidity is high in sulphuric acid, but baseness is low in ammonium hydroxide. As a result, the acidity of the salt generated by ammonium sulphate is high. It is a salt that, when dissolved in a solution, will generate a basic solution of the same name. It is possible to produce basic salts by neutralising strong bases with weak acids. Ammonium sulphate is a salt formed by the reaction of a strong acid and a weak base, and as such it is an acidic salt.

6. When sulphuric acid reacts with eggshell it produces

1. 1. hydrogen gas
   2. nitrogen gas
   3. carbon monoxide
   4. carbon dioxide gas

Answer: (D)

Eggshell interacts with sulphuric acid, resulting in the formation of calcium oxide and the release of carbon dioxide gas as byproducts. Sulphuric acid reacts with eggshell calcium carbonate, which is abundant in eggshells. Calcium carbonate is the main component of the eggshell. When nitric acid is introduced to eggshells, it causes the creation of calcium nitrate and carbon dioxide gas, which is harmful to the environment. Calcium Nitrate + Carbon Dioxide + Water = Eggshell + Nitric Acid + Carbon Dioxide + Water.

7. In the Chlor-alkali process, the byproduct gases are

1. 1. hydrogen only
   2. hydrogen and oxygen gas
   3. hydrogen and chlorine gas
   4. chlorine and nitrogen gas

Answer: (C)

Chlor-alkali is an industrial process that is widely used to produce chlorine, caustic soda, and other chlorine-and-sodium-derived/based products such as sodium hypochlorite, hydrochloric acid, chlorosulphonic acid, bleaching powder, polyaluminum chloride (plastic aluminium chloride), hydrogen gas (gaseous hydrogen), and chlorinated paraffin. Bleaching powder is a bleaching agent that is commonly used in the chemical industry. As a result, chlorine gas is produced as a by-product of the chlor-alkali process, which is employed in the production of bleaching powder.

8. The following salt is not hygroscopic in nature

1. 1. NaCl
   2. MgCl
   3. CaCl2
   4. KCl

Answer: (A)

In nature, none of the salts are hygroscopic at all. The pure form of sodium salt, sodium chloride, is incapable of absorbing water from only the surrounding atmosphere of wet air. When there is little humidity, NaCl does not alter.

9. When more and more water is diluted with acids its H+ ion concentration will

1. 1. increase
   2. decrease
   3. remains the same
   4. depends on the type of acids

Answer: (B)

10. When acids react with metal oxide it produces

1. 1. water and salt
   2. salts and hydrogen gas
   3. salts only
   4. no reaction takes place

Answer: (A)