CBSE 11TH CHEMISTRY - Online Test
Q1. Gases have much lower density than the solids and liquids because ?
Answer : Option D
Explaination / Solution:
In gases, molecules are far apart from each other, thermal energy which is a measure of freeness of motion is thus very high resulting in a very large volume for the same mass(compared to solid and liquid). Hence there density is lowest.
Q2. The mass of a gas dissolved in a given mass of a solvent at any temperature is proportional to the pressure of the gas above the solvent.
Answer : Option A
Explaination / Solution:
This equilibrium is governed by Henry’s law, which states that the mass of a gas dissolved in a given mass of a solvent at any temperature is proportional to the pressure of the gas above the solvent. This amount decreases with increase of temperature.
Q3. boiling point of alkanes
Answer : Option B
Explaination / Solution:
As molecular mass increases,the magnitude of van der Waals forces of attraction increases and hence boiling point increases accordingly.
Q4. In the reaction of metallic cobalt placed in nickel sulphate solution, there is a competition for release of electrons At equilibrium, chemical tests reveal that both Ni2+ (aq) and Co2+ (aq) are present at moderate concentrations. The result is that:
Answer : Option A
Explaination / Solution:
Reaction will not complete and It will remain at equilibrium.
Q5. The molar heat capacity of a substance is the
Answer : Option C
Explaination / Solution:
The molar heat capacity of a substance is the quantity of heat needed to raise the temperature of one mole by one degree Celsius.
Q6. According to the recommendation of International Union of Pure and Applied Chemistry (IUPAC), the groups in the modern periodic table are numbered from
Answer : Option C
Explaination / Solution:
The groups are numbered from 1 to 18; where group 1 is alkali metal group and group 18 is for the noble gases.
Q7. Isotopes are the atoms with
Answer : Option D
Explaination / Solution:
The atoms of a chemical element can exist in different types. These are called isotopes. They have the same number of protons (and electrons), but different numbers of neutrons. Different isotopes of the same element have different masses.
Q8. Acid rain is :
Answer : Option A
Explaination / Solution:
The acidic gaseous pollutants like oxides of sulphur and nitrogen react with water and come down to earth in form of acid rain.
Q9. For the synthesis of methanol and a number of hydrocarbons , the compounds used are
Answer : Option B
Explaination / Solution:
A mixture of CO and H2 in any ratio is called synthesis gas or syn gas as it is used in synthesis of methanol and a number of hydrocarbon.
Q10. A qualitative measure of the stability of an ionic compound is provided by
Answer : Option C
Explaination / Solution:
Lattice energy is an estimate of the bond strength in ionic compounds. It is defined as the heat of formation for ions of opposite charge in the gas phase to combine into an ionic solid.
The stability of ionic bond is directly propotional to lattice energy.
