Chemistry (Part-VI)

11. The boiling point of liquids varies as- [S.S.C. Online Graduate Level (T-I) 27.08.2016]

(a) Pressure varies
(b) Temperature varies
(c) Volume varies
(d) Density varies

Correct Answer: (a) Pressure varies

Solution:Pressure varies - The boiling point of a liquid is the temperature at which its vapor pressure equals the surrounding atmospheric pressure. Therefore, as the pressure changes, the boiling point also changes. For instance, water boils at a lower temperature at higher altitudes where the atmospheric pressure is lower.

12. An eudiometer measures- [S.S.C. Online Graduate Level (T-I) 2.09.2016]

(a) Atmospheric pressure
(b) Time
(c) Volume of gases
(d) Vapour pressure

Correct Answer: (c) Volume of gases

Solution:Volume of gases - An eudiometer is a laboratory apparatus used to measure the volume of gases produced or consumed in a chemical reaction.

13. Which of the following has pH value 7? [S.S.C. Online Graduate Level (T-I) 11.09.2016]

(a) Pure Water
(b) sulfuric acid
(c) Sodium Carbonate
(d) HCI

Correct Answer: (a) Pure Water

Solution: Pure Water - Pure water is considered neutral and has a pH value of 7 at

2 5^{\circ} C

.Sulfuric acid is a strong acid (pH < 7), sodium carbonate is a basic salt (pH > 7), and hydrochloric acid is a strong acid (pH t< 7).

14. The pH of a liquid was found to be 7. Which liquid is it likely to be? [S.S.C. Online CHSL (T-I) 18.03.2020]

(a) Water
(b) Acid
(c) Alkali
(d) Saline

Correct Answer: (a) Water

Solution:Pure water has a pH of 7. The pH value is actually a measure of the concentration of hydrogen ions in a liquid, by which the acidity or alkalinity of a liquid is checked. Liquids with a pH value less than 7 are acidic and liquids with a pH value greater than 7 are alkaline in nature. The pH value of water is 7 which means that it is a neutral liquid, but only for pure water this value is approximately equal to 7.

15. What is the neutral value of the pH scale? [S.S.C. Online Constable GD 18.02.2019]

(a) More than 7
(b) Equal to 7
(c) less than 7
(d) Equal to 14

Correct Answer: (b) Equal to 7

Solution:Equal to 7 - The pH scale ranges from 0 to 14, with 7 being the neutral point. Values below 7 indicate acidic solutions, and values above 7 indicate basic (or alkaline) solutions.

16. What is the pH of water? [S.S.C. Online CHSL (T-1) 19.01.2017]

(a) 7
(b) 5
(c) 3
(d) 1

Correct Answer: (a) 7

Solution:7 - The pH of pure water at

2 5^{\circ} C

is 7, which signifies its neutral nature.

17. What is the pH value of acidic substances? [S.S.C. Online C.H.S.L. (T-1) 12.08.2021]

(a) Below 7.0
(b) Below 4.0
(c) Below 2.0
(d) Below 1.0

Correct Answer: (a) Below 7.0

Solution:Below 7.0 - Acidic substances have a pH value less than 7. The lower the pH value, the stronger the acid.

18. What does 'p' stand for in pH? [S.S.C. Online M.T.S. (T-I) 13.10.2021]

(a) Precipitation
(b) Potency
(c) Potenz
(d) Percentage

Correct Answer: (c) Potenz

Solution:

Potenz - The 'p' in pH stands for 'Potenz', which is German for 'power' or 'potential', referring to the power of hydrogen ion concentration.

19. pH of lemon juice is 4, which means it is ________ . [S.S.C. Online MTS (T-I) 3.10.2017]

(a) Basic
(b) Acidic
(c) Neutral
(d) None of these

Correct Answer: (b) Acidic

Solution:Acidic - A pH value of 4 is below 7, indicating that lemon juice is acidic.

20. Which of the following substances have a pH value that is closest to zero? [S.S.C. Online MTS (T-I) 20.08.2019]

(a) Concentrated Hydrochloric Acid (HCI)
(b) Baking soda
(c) Ammonia
(d) Pure water

Correct Answer: (a) Concentrated Hydrochloric Acid (HCI)

Solution: Concentrated Hydrochloric Acid (HCl) - The pH scale ranges from 0 to 14, with lower values indicating higher acidity. Concentrated hydrochloric acid is a strong acid and will have a pH value closest to zero among the given options. Baking soda is basic (pH > 7), ammonia is also basic (pH > 7), and pure water is neutral (pH = 7).