Practice problems on JEE Mains, JEE Mains 2001

Question 1

If for a reaction A⟶B,ΔH=−10 kJ mol−1 and Eα​=50 kJ mol−1, then the energy of activation for reaction B⟶A will be

Accepted Answer

60 kJ mol−1

Answer

40 kJ mol−1

Answer

50 kJ mol−1

Answer

−50 kJ mol−1

Question 2

The complex showing a spin-only magnetic moment of 2.82BM is

Accepted Answer

[NiCl4​]2−

Answer

[Ni(CN)4​]2−

Answer

Ni(CO4​)

Answer

Ni(PPh3​)4​

Question 3

IUPAC name of the compound is

Accepted Answer

propane-1,2,3-tricarboxylic acid

Answer

2-carboxylic pentane-1, 5-dioic acid

Answer

iso-butane-1, 2, 3-tricarboxylic acid

Answer

butane-1, 2, 3-tricarboxylic acid

Question 4

Which reagent can be used to identify nickel ion?

Accepted Answer

Dimethyl glyoxime

Answer

Resorcinol

Answer

Diphenyl benzidine

Answer

Potassium ferrocyanide

Question 5

Magnetic moments of Cr(Z=24), Mn (Z=25) and Fe(Z=26) are x,y and z respectively. Hence,

Accepted Answer

x>y>z

Answer

x=y=z

Answer

x=z<y

Answer

x<y<z

Question 6

Of the following acids I. Hypophosphorous acid II. Orthophosphorous acid III. Caro's acid IV. Glycine

Accepted Answer

I monobasic; II, III dibasic acid and IV amphoteric

Answer

I, II monobasic; III dibasic acid and IV amphoteric

Answer

II monobasic; I, III dibasic acid and IV amphoteric

Answer

I, II, III dibasic acids and IV amphoteric

Question 7

Phenolphthalein is an indicator for acid-base titration, it exists as

Accepted Answer

benzenoid form in acid and quinonoid form in basic solution

Answer

quinonoid form in acid and benzenoid form in basic solution

Answer

quinonoid form in both

Answer

benzenoid form in both

Question 8

p-toluidine and benzyl amine can be distinguished by

Accepted Answer

Dye test

Answer

Sandmeyer's reaction

Answer

Molisch test

Answer

Gattermann reaction

Question 9

Phenolphthalein is an indicator for acid-base titration, it exists as

Accepted Answer

benzenoid form in acid and quinonoid form in basic solution

Answer

quinonoid form in acid and benzenoid form in basic solution

Answer

quinonoid form in both

Answer

benzenoid form in both

Question 10

What are the four quantum numbers of the 19th electron in scandium (at. no. 21)?

Accepted Answer

n=4,l=0,m=0,ms​=+21​

Answer

n=4,l=0,m=0,ms​=−21​

Answer

n=4,l=0,m=1,ms​=+21​

Answer

n=4,l=1,m=−1,ms​=+21​

Question 11

Among the following species, identify the isostructural pairs NH3​,ClO3−​,NO3−​,SF5⊕​,PCl5​ and BF3​

Accepted Answer

(BF3​,NO3−​)and (SF5+​,PCl5​)

Answer

(NH3​,ClO3−​)and (SF5+​,PCl5​)

Answer

(ClO3−​,NO3−​)and (NH3​,PCl5​)

Answer

(BF3​,NH3​) and (SF5⊕​,PCl5​)