CBSE 11TH CHEMISTRY - Online Test
Q1. Gay Lussac’s law states that at constant volume, pressure of a fixed amount of a gas
Answer : Option A
Explaination / Solution:
P α T (at constant V).
Q2. At a given temperature equilibrium is possible only in a system which is a
Answer : Option D
Explaination / Solution:
Equilibrium is possible only in a closed system at a given temperature for physical processes. When equilibrium is attained for a physical process, it is characterized by constant value of one of its parameters at a given temperature.
Q3. Carbon-carbon double bond in alkenes consists of
Answer : Option A
Explaination / Solution:
sigma bond is formed by head-on overlap of sp2 hybridised orbitals while the pi bond is formed by lateral or sideways overlapping of the two 2p-orbitals of the two carbon atoms. Alkenes contain 1 weak pi bond and 1 strong sigma bond.
Q4. Aurous chloride and auric chloride are written as Au(l)Cl and Au(lll)Cl3.The roman numeral in parenthesis after the symbol of the metal in the molecular formula represents the
Answer : Option C
Explaination / Solution:
The roman number represents the oxidation number/oxidation state of an element.It is popularly known as Stock notation given by the german scientist Alfred stock.
Q5. An exothermic process
Answer : Option A
Explaination / Solution:
Exothermic process results in decrease in enthalpy of system hence for exothermic reaction ΔH= -ve.
Q6. Atomic number of element Unnilhexium is:
Answer : Option D
Explaination / Solution:
un=1 Nil=0 Hex=6 So 106=uninilhexium.
Q7. Absorption spectrum, seen as dark lines in an otherwise continuous spectrum, for a given material results from the material's (atom or molecules)
Answer : Option A
Explaination / Solution:
In an absorption spectrum, portions of a continuous spectrum (light containing all wavelengths) are missing because they have been absorbed by the medium through which the light has passed; the missing wavelengths appear as dark lines or gaps.
Q8. Hydrocarbons are formed by :
Answer : Option A
Explaination / Solution:
Hydrocarbons are formed by incomplete combustion of fossil fuels used in automobiles. When they undergo incomplete combustion, they are partially oxidised and produce other fragments of hydrocarbons along with CO and C.
Q9. Dihydrogen under certain reaction conditions, combines with almost all elements to form binary compounds, called hydrides except with few which are given below Choose one of the options
Answer : Option D
Explaination / Solution:
Noble gases are inert and have high ionisation enthalpy. Hence, they do not form any hydrides.
Q10. The amount of energy required to break one mole of bonds of a particular type between two atoms in a gaseous state is called
Answer : Option D
Explaination / Solution:
Bond enthalpy, also known as bond energy, is the energy that is needed to break a particular bond in a gaseous compound. The unit that expresses bond enthalpy is kilojoules per mole, or kJ/mol.
