Acids & Bases — Set 3
Chemistry · अम्ल और क्षार · Questions 21–30 of 60
Which acid is used in lead storage batteries?
Correct Answer: B. Sulfuric acid
Sulfuric acid acts as the electrolyte in lead-acid batteries used in cars and inverters. It facilitates the flow of electrons between the lead plates during charging and discharging. The concentration of the acid changes as the battery operates.
What is the pH of human blood?
Correct Answer: D. 7.35 - 7.45
Human blood is slightly basic and its pH is strictly maintained between 7.35 and 7.45. Any significant deviation from this range can be fatal for the human body. Buffer systems in the blood help regulate this constant pH level.
Which of the following is a weak base?
Correct Answer: B. Ammonium hydroxide
Ammonium hydroxide is a weak base because it does not ionize completely in water. It is commonly used in household cleaners and for removing grease from windows. Strong bases like sodium hydroxide ionize fully into their constituent ions.
What color does methyl orange turn in an acidic solution?
Correct Answer: A. Red
Methyl orange is a synthetic indicator that turns red in acidic environments. It turns yellow in basic or neutral solutions. It is often used in titrations because of its very clear and distinct color change.
Which of the following acids is also known as Vitamin C?
Correct Answer: D. Ascorbic acid
Ascorbic acid is the chemical name for Vitamin C, an essential nutrient for humans. It is found abundantly in amla and citrus fruits and helps in building immunity. Deficiency of this acid can lead to a disease called scurvy.
Which chemical is used to neutralize soil that is too acidic?
Correct Answer: A. Quick lime
Quick lime (calcium oxide) is a basic substance used by farmers to neutralize acidic soil. This process improves soil quality and ensures better growth for most crops. Excessive use of chemical fertilizers often leads to increased soil acidity.
Which acid is used for cleaning gold and silver ornaments?
Correct Answer: A. Nitric acid
Nitric acid is used in the form of Aqua Regia or alone to clean and refine precious metals. It reacts with surface impurities to restore the shine of the ornaments. It is a highly corrosive and strong mineral acid.
What is the scale used to express the acidity or alkalinity of a substance?
Correct Answer: A. pH scale
The pH scale measures the concentration of hydrogen ions in a solution. It was introduced by S.P.L. Sørensen in 1909. Values below 7 are acidic, while values above 7 are basic.
Which of the following is a natural indicator?
Correct Answer: B. Red cabbage juice
Red cabbage juice contains anthocyanins that change color based on the acidity of the solution. It turns red in acids, purple in neutral solutions, and greenish-yellow in bases. It is a popular natural alternative to laboratory indicators.
Which acid is found in curd and sour milk?
Correct Answer: A. Lactic acid
Lactic acid is produced when bacteria ferment the lactose sugar present in milk. This process turns milk into curd and gives it a characteristic sour taste. It is also produced in human muscles during strenuous exercise.