Chemistry PYQ — Page 2

Which one among the following is called philosopher's wool?

Assertion (A): Cellulose is used in making shatter-proof glass. Reason (R): Polysaccharides are not soluble in water. Codes:

Consider the following chemicals: 1. Benzene 2. Carbon tetrachloride 3. Sodium carbonate 4. Trichloroethylene Which of the above/is are used as dry cleaning chemical?

Which are the materials generally employed as solder in soldering operations in electronics?

Assertion (a) :The main constituent of the liquefied petroleum gas is methane. Reason (R): Methane can be used directly for burning in homes and factories where it can be supplied through pipelines.

Which one of the following is the correct sequence of the given substances in the decreasing order of their densities?

Consider the following statements: 1. Baking soda is used in fire extinguishers. 2. Quick lime is used in the manufacture of glass. 3. Gypsum is used in the manufacture of plaster of Paris. Which of the statements given above is/are correct?

Match List-I (Fuel gases) with List-II (Major constituents) and select the correct answer using the codes given below the lists: | List I | | List II A. | CNG | 1. | Carbon monoxide, Hydrogen B. | Coal Gas | 2. | Butane, Propane C. | LPG | 3. | Methane, Ethane D. | Water Gas | 4. | Hydrogen, Methane, Carbon monoxide Code: A B C D

Salts of which of the following elements provide colours to fireworks?

Assertion (A): Unsaturated fats are more reactive compared with the saturated fats. Reason (R): Unsaturated fats have only single bonds in their structure.

Assertion (a) : In the periodic table of chemical elements, electron affinity is always found to increase from top to bottom in a group Reason (R): In a group, the atomic radii generally increase from top to bottom.

Regarding the atom of a chemical element, the magnetic quantum number refers to

With reference to ionic compounds, consider the following statements: 1. Ionic compounds are insoluble in alcohol. 2. Ionic compounds in the solid state are good conductor of electricity. Which of these statements is/are correct?

Which one of the following statements is NOT correct?

The purpose of adding sodium sulphate and sodium silicate to the detergent in a washing powder is 1. to keep the washing powder dry. 2. to maintain the alkalinity of the powder. Which of these statements is/are correct?

Assertion (A): With the increase of temperature, the viscosity of glycerine increases. Reason (R): Rise of temperature increases kinetic energy of molecules.

Assertion: Synthetic detergents can lather well in hard water. Reason (R): Synthetic detergents form soluble calcium and magnesium salts with hard water.

Match List-I (Oxidation number) with List II (The element) and select the correct answer using the codes given below the lists: | List-I (Oxidation number) | | List-II (The elements) A. | 2 | 1. | Oxidation number of Mn in MaO2 B. | 3 | 2. | Oxidation number of S in \(H_{2}S_{5}O_{7}\) C. | 4 | 3 | Oxidation number of Ca in CaO D. | 6 | 4. | Oxidation number of Al in NaA1H4 Codes: ABCD

Which one of the following is the correct sequence in increasing order of molecular weights of the hydrocarbons?

An aqueous solution of copper sulphate is acidic in nature because the salt undergoes

In an atom, the order of filling up of the orbitals is governed by

Consider the following statements with reference to the periodic table of chemical elements: 1. lonisation potential gradually decreases 'along a period. 2. In a group of elements, electron affinity decreases as the atomic weight increases. 3. In a given period, electronegativity decreases as the atomic number increases. Which of these statements(s) is/are correct?'

Which one of the following materials is very hard and very ductile?

Assertion (A): Large cold storage plants use ammonia as refrigerant while domestic refrigerators use chlorofluorocarbons. Reason (R): Ammonia can be liquified at ambient temperatures at low pressures.