1 Hydrocarbons
Addition of HI on double bond of propene yields iso-propyl iodide as major product. It is because the addition process through 1) Homolysis 2) More stable carbocation 3) More stable carbanion 4) More stable free radica
SOLUTION
2 Electrochemistry
In electro-refining of copper some gold is deposited as :
1) Electrolyte 2) Cathode 3) Cathode mud 4) Anode mud
3 S – Block Elements
The sulphate of which metal given below has the highest solubility in water?
1) Ca 2) Ba 3) Sr 4) Mg
On moving down the group of alkaline earth metals, the solubility of metal sulphates decreases. Also, the ionic size increases and hydration energy of metal ion decreases. Hence, magnesium sulphate(MgSO4) has lowest solubility.
4 Basic Principles of Organic Chemistry
How many stereoisomers are therefor tartaric acid? 1) 2 2) 3 3) 4 4) 5
d-tartaric acid, l-tartaric acid,meso-tartaric acid
5 Basic Concepts of Chemistry
Which orbital is represented by the complete wave function Y 420?
1) 4p
2) 3d
3) 3p
4) 4s
Solution
Orbital are represented by the wavefunction $${ \psi }_{ n,l,m }$$
Given wavefunction is $${ \psi }_{ 420 }$$
Thus $$n=4$$
$$l=2$$$$\rightarrow $$d-orbital
So, the orbital is $$4d$$
6 S – Block Elements
What is the correct order of increasing solubility of the following salt?
In the give metal bicarbonates, the anion (bicarbonate ion) is same. Hence the solubility will depend on the size of anion. The size of $$Na^+$$ ion is smaller than that of $$K^+$$ ion. Hence sodium bicarbonate has high lattice energy and lower solubility than potassium bicarbonate. Similarly, the size of $$Mg^+$$ ion is smaller than that of $$Ca^+$$ ion. Hence magnesium bicarbonate has high lattice energy and lower solubility than calcium bicarbonate.
7 Surface Chemistry
KClO3 on heating decomposes into KCl and O2. If some MnO2 is added, the reaction goes much faster because :
1) MnO2 decomposes to give oxygen 2) MnO2 acts as a catalyst 3) better contact is provided by MnO2 4) MnO2 provides heat by reacting
The reaction is as follows: 2KClO3−---heat → 2KCl + 3O2 In this reaction, if MnO2 is used, then the reaction become faster due to catalytic activities of MnO2
(Catalyst is a substance which lowers activation energy of reaction because it provides alternate pathway for reaction. Also, it increases the rate of backward and forward reaction with same extent. Due to this lower activation energy, equilibrium is attained faster but it doesnot change the overall enthalpy of the reaction.)
8 Atomic Structure
Consider the following statements,. the d-orbitals have (i) four lobes and two nodes (ii) four lobes and one node (iii)same sign in opposite lobs (iv)opposite sign in the opposite lobs 1) i alone 2) i and iii 3) ii and iii 4) i and iv
d-orbital have four lobes and two nodes and opposite lobes have the same sign
9 Alcohols Phenols and Ethers
Phenol is most easily soluble in 1. sodium carbonate solution 2. sodium hydroxide solution 3. dilute HCl 4. both sodium hydroxide and dilute HCl
10 Redox Reactions
If 1mL of a KMnO4 solution react with 0.140 g Fe2+ .140 g Fe2+ and if 1mL1mL of KHC2O4. H2C2O4 solution react with 0.1mL of previous KMnO4 solution, how many millilitres of 0.20M NaOH will react with 1mL of previous KHC2O4. H2C2O4 solution in which all the protons (H+) are ionisable?
1) 15 / 16mL 2) 13/ 16 3) 11 / 14 4) None
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