1. Oxygen only
2. Oxygen and nitrogen
3. Hydrogen and carbon
4. Oxygen and carbon
Option “A” is correct Ozone (O3), or trioxygen, is a triatomic molecule, consisting of three oxygen atoms.
232. Which among the following is white phosphorus?
1. P1
2. P6
3. P4
4. P5
Option “C” is correct The most important form of elemental phosphorus from the perspective of applications and chemical literature is white phosphorus. It consists of tetrahedral P4 molecules, in which each atom is bound to the other three atoms by a single bond.
233. Which among the following is present inside the nucleus of anatom?
1. Protons and Neutrons
2. Electrons and Protons
3. Neutrons and Electrons
4. Neutrons, Protons, Electrons
Option “A” is correct There are two types of particle in the nucleus of an atom the proton and the neutron.
Option “C” is correct Baking soda is also known as Sodium bicarbonate. It is a chemical compound with the formula NaHCO3 It is a salt composed of sodium ions and bicarbonate ions. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder.
235. Which among the following elements is a liquid at room temperature?
1. Phosphorus
2. Mercury
3. Sodium
4. Aluminum
Option “B” is correct There are two elements that are liquid in room temperature which are Bromine (Br) and Mercury (Hg).
236. Which among the following is an endothermic reaction?
1. Respiration
2. Combustion
3. Sweating
4. Burning of natural gas
Option “C” is correct Endothermic process describes a process or reaction in which the system absorbs energy from its surroundings. Sweating is a endothermic reaction.
237. Who discovered benzene?
1. Hal Anger
2. Michael Faraday
3. Bruce Ames
4. Nicolas Appert
Option “B” is correct Benzene was first discovered by the English scientist Michael Faraday in 1825
238. The pH of lemon juice is expected to be—
1. More than 7
2. Equal to 7
3. Nothing can be predicted
4. Less than 7
Option “D” is correct Lemons are acidic. Any chemical with a pH less than 7 is considered acidic. Lemon juice has a pH around 2.0.
Option “A” is correct Vinegar consists of acetic acid and water. A small amount of sugar and fruit juice may be added to vinegar as a flavouring agent.
240. Which of the following do not consist carbon?
1. Diamond
2. Graphite
3. Coal
4. None of these
Option “D” is correct Diamond is an additional form of Carbon. Its relative density is 3.5 Graphite is a slaty-black coloured smooth and brightly organic matter of relative density 2.25, while coal is a solid organic matter used as fuel. All the three are consist of carbon.
