CBSE 11TH CHEMISTRY - Online Test
Q1. In Daniell cell, direction of current is
Answer : Option D
Explaination / Solution:
Current is taken at the direction in which positive charge is flowing, but electrons are negatively charged. So, the direction of current and the direction of electron flow is opposite.
Q2. Spontaneity in the context of chemical thermodynamics means
Answer : Option C
Explaination / Solution:
spontaneity means a reaction occurring on its own without any help of external agency.
Q3. f-block of the Periodic Table consists of
Answer : Option C
Explaination / Solution:
The two rows of elements at the bottom of the Periodic Table, called the Lanthanoids, Ce(Z = 58) – Lu(Z = 71) and Actinoids, Th(Z = 90) – Lr (Z = 103) are characterised by the outer electronic configuration (n-2)f1-14 (n-1)d0-1 ns2. The last electron added to each element is filled in f- orbital. These two series of elements are hence called the Inner- Transition Elements (f-Block Elements).
Q4. According to quantum mechanics ψ2(r) the wave function squared gives
Answer : Option D
Explaination / Solution:
Probability density of finding an electron at a point with in an atom, it is posible to predict region around the nucleus where electron can most probably be found.
ψ has no physical significance while ψ2 represnts the probability density of finding an electron.
Q5. The gas released during volcanic eruptions is :
Answer : Option C
Explaination / Solution:
CO2 is the second most abundant gas released in volcanic eruption after water vapours.
Q6. The calculation of masses or, (sometimes volumes also) of the reactants and the products involved in a chemical reaction is called
Answer : Option B
Explaination / Solution:
Stoichiometry is a method to express quantitative aspects of a chemical reaction .
Usually , the masses of reactants as well as those of products in a chemical reaction are calculated using corresponding balanced chemical equation .
It is convenient and hence desirable to calculate volumes of gaseous reactants and products .
Q7. presence of extensive hydrogen bonding between water molecules leads to
Answer : Option C
Explaination / Solution:
Water has high freezing point and boiling point because of strong intermolecular hydrogen bonding interactions.
Q8. in case of a heteronuclear molecule like HF, the shared electron pair between the two atoms gets displaced more towards fluorine since the electronegativity of fluorine is far greater than that of hydrogen. This results in the molecul
Answer : Option C
Explaination / Solution:
because of slight shifting of electron towards more electronegative element like F in HF brings a small amount of negative charge on F and positive charge on H which results in dipole moment.
Q9. The nitrogen containing organic compound, when heated with copper oxide in an atmosphere of carbon dioxide, yields:
Answer : Option C
Explaination / Solution:
The nitrogen containing organic compound, when heated with copper oxide in an atmosphere of carbon dioxide, yields free nitrogen
Q10. Lithium has most negative value,its reaction with water is less vigorous than that of sodium which has the least negative E0 value among the alkali metals. The reason is
Answer : Option D
Explaination / Solution:
Li due its small size have high Lattice energy value which compensates its high ionization energy so has most negative value
