Step 1: Identification of Lung Irritants : Causes respiratory issues and lung inflammation. , , and are not primary lung irritants.
02
PYQ 2024
medium
chemistryID: ap-eamce
Which of the following is/are estimated by titrating polluted water with potassium dichromate solution in acidic medium?
1
I only
2
II only
3
II \& III only
4
I, II, III
Official Solution
Correct Option: (1)
Step 1: Understanding the Estimation of Pollutants Chemical Oxygen Demand (COD) is a measure of the total amount of oxygen required to oxidize both organic and inorganic pollutants in water. It is determined by titrating the sample with potassium dichromate in acidic medium. Step 2: Why Only COD? - COD estimation involves potassium dichromate in an acidic medium.
- Biochemical Oxygen Demand (BOD) measures oxygen consumption by microorganisms, typically determined using a different method. - Dissolved Oxygen (DO) is estimated using the Winkler’s method, not potassium dichromate. Thus, only COD (I) is estimated using potassium dichromate titration.
03
PYQ 2024
medium
chemistryID: ap-eamce
Match the pollutant in List I with its maximum permissible limit in drinking water given in List II.
1
A-I, B-II, C-I
2
A-II, B-I, C-III
3
A-III, B-I, C-II
4
A-III, B-II, C-I
Official Solution
Correct Option: (3)
List I: Pollutants in drinking water and their maximum permissible limits: - Lead (A): The maximum permissible limit of Lead in drinking water is 50 ppb (part per billion). So, A matches with III. - Sulphate (B): The maximum permissible limit of Sulphate in drinking water is 500 ppm (parts per million). So, B matches with I. - Nitrate (C): The maximum permissible limit of Nitrate in drinking water is 50 ppm. Hence, C matches with II. Thus, the correct match is A-III, B-I, C-II.
04
PYQ 2024
medium
chemistryID: ap-eamce
Two statements are given below: I. In dry cleaning, the solvent = was earlier used and now it is replaced by liquefied . II. In bleaching of paper, was used earlier and now it is replaced by chlorine gas.
1
Statements I, II both are correct
2
Statements I, II both are incorrect
3
Statement I is correct but statement II is incorrect
4
Statement I is incorrect but statement II is correct
Official Solution
Correct Option: (3)
- Statement I: In dry cleaning, the solvent used was previously = , but due to environmental concerns, it has been replaced by liquefied , which is safer and more environmentally friendly. Thus, Statement I is correct.
- Statement II: In the bleaching of paper, chlorine gas is not used as a replacement for . is still used in most bleaching processes. Therefore, Statement II is incorrect. Thus, the correct answer is option (3), where Statement I is correct and Statement II is incorrect.
05
PYQ 2024
medium
chemistryID: ap-eamce
Arrange the following pesticides in the chronological order of their release into the market: A: Organophosphates
B: Organochlorides
C: Sodium chlorate
1
B, A, C
2
B, C, A
3
C, B, A
4
A, B, C
Official Solution
Correct Option: (1)
Step 1: Understanding pesticide classifications
- Organochlorides (B): These were among the earliest synthetic pesticides introduced in the 1940s. Examples include DDT.
- Organophosphates (A): These were developed later to replace organochlorides due to environmental concerns.
- Sodium chlorate (C): This is a herbicide that became widely available later.
Step 2: Arranging them chronologically Since Organochlorides were developed first, followed by Organophosphates, and finally Sodium Chlorate, the correct order is:
