CBSE 11TH CHEMISTRY - Online Test

Answer : Option A
Explaination / Solution:

t is restatement of law of conservation of energy. It states that Thermodynamics isthe branch of physical science that deals with the relations between heat and other forms of energy (such as mechanical, electrical, or chemical energy), and, by extension, of the relationships between all forms of energy.

Answer : Option C
Explaination / Solution:

In 1909, Robert Millikan and Harvey Fletcher conducted the oil drop experiment to determine the charge of an electron. They suspended tiny charged droplets of oil between two metal electrodes by balancing downward gravitational force with upward drag and electric forces. The experiment helped earn Millikan a Nobel prize in 1923

Answer : Option A
Explaination / Solution:

Vegetables have cell walls made up of cellulose which is a natural polymer and thus is bio-degradable, so they breakdown by natural processes.

Answer : Option A
Explaination / Solution:

Due to unfavourable neutron to proton ratio, tritium emits low energy beta particles.

Answer : Option A
Explaination / Solution:

Chemical bond formed between two atoms due to transfer of electron(s) from one atom to the other. atom is called "Ionic bond" or "electrovalent bond". in electrovalent bond one atom loses an electron to form a positive ion and the other atom gains the electron to form a negative ion. The resulting ions are held together by electrostatic attraction

Answer : Option C
Explaination / Solution:

According to the modern concept, loss of electrons is oxidation whereas gain of electrons is reduction.Redox reaction involves two half reactions, one involving loss of electron or electrons (oxidation) and the other involving gain of electrons or electrons (reduction)

• Oxidizing agent is a species which can gain one or more electrons.
• Reducing agent is a species which can lose one or more electrons.

In the given reaction Sodium(Na) is loosing 2 electrons, thus it is the reducing agent. Chlorine(Cl) is gaining 2 electrons , thus it is oxidising agent.

Answer : Option D
Explaination / Solution:

Alkaline earth metals are called so because of two reasons

1. Alkaline earth metals are obtained on earth in the form of ores
2. Oxides and hydroxides of Alkaline earth metals are basic in nature,

However Beryllium fulfills 1st reason but its oxides and hydroxides are amphoteric so sometimes they say it is not alkaline earth metal. but as it is amphoteric IUPAC has accepted this as alkaline earth metal

Answer : Option A
Explaination / Solution:

C in H2C=O is sp2 hybridised and geometry is planar.

Answer : Option B
Explaination / Solution:

Pure substances have fixed composition..These may be both (ie. either elements or compounds ) . The law of constant composition holds good for such substances .

Answer : Option D
Explaination / Solution:

The number of water molecules from the gaseous state into the liquid state also increases till the equilibrium is attained i.e., rate of evaporation = rate of condensation At equilibrium the pressure exerted by the water molecules at a given temperature remains constant and is called the equilibrium.