CBSE 11TH CHEMISTRY - Online Test
Q1. The relative tendency of an atom in a molecule to attract the shared pair of electrons towards itself is termed as its
Answer : Option D
Explaination / Solution:
A qualitative measure of the ability of an atom in a chemical compound to attract shared electrons to itself is called electronegativity. Unlike ionization enthalpy and electron gain enthalpy, it is not a measureable quantity. However, a number of numerical scales of electronegativity of elements viz., Pauling scale, Mulliken-Jaffe scale, Allred-Rochow scale have been developed. The electronegativity of any given element is not constant; it varies depending on the element to which it is bound.
Q2. Holes in the ozone layer are thought to have been caused by:
Answer : Option A
Explaination / Solution:
CFC’s causes hole in the ozone layer.
Q3.
Give the number of electrons in the species, and .
Answer : Option C
Explaination / Solution:
atomic number O has atomic number = 8 so number of electrons in = 16
while in there is one unit positive charge so no. of electron =15.
Q4. When sodium peroxide is treated with dilute sulphuric acid, we get ______.
Answer : Option C
Explaination / Solution:
Hydrogen peraoxide is also prepared by the reaction of acid sodium peroxides. Reaction is as follow :
Q5. The state of a gas can be described by quoting the relationship between
Answer : Option C
Explaination / Solution:
State of gas is determined by stating the value of P,V,n,T
Q6. In acetylene molecule, between the carbon atoms there are
Answer : Option D
Explaination / Solution:
acetylene is C2H2.
C atoms are bound with triple bond i.e. 1 sigma and 2 pie bonds.
Q7. Alkali metals react with water vigorously to form hydroxides and dihydrogen.Which of the following alkali metals reacts with water least vigorously?
Answer : Option C
Explaination / Solution:
Li reacts with water least vigorously, since the density of Li is only about half that of water,so it floats on the surface and ultimately dissappears,giving off H2 gas
Q8. Delocalisation of σ electrons of C -H bond of an alkyl group directly attached to an atom of unsaturated system or to an atom with an unshared p orbital is called:
Answer : Option B
Explaination / Solution:
Delocalisation of σ electrons of C -H bond of an alkyl group directly attached to an atom of unsaturated system or to an atom with an unshared p orbital is known as Hyperconjugation
Q9. A plot of volume (V ) versus temperature (T ) for a gas at constant pressure is a straight line passing through the origin. The plots at different values of pressure are shown in Figure. Which of the following order of pressure is correct for this gas?
Answer : Option B
Explaination / Solution:
keep Temperature constant we know Pα1/V So as V increases P decreases.
Q10. Molecular formula represents
Answer : Option B
Explaination / Solution:
Molecular formula is the exact no. of atoms present in a molecule of a compound.
Molecular formula of a compound is related with its empirical formula as ,
Mollecular formula = ( Empirical formula ) n
where n represents a positive integer .
