List of top Questions asked in JEE Main

Compound $A , C _5 H _{10} O _5$, given a tetraacetate with $AC _2 O$ and oxidation of $A$ with $Br _2- H _2 O$ gives an acid, $C _5 H _{10} O _6$ Reduction of $A$ with $HI$ gives isopentane The possible structure of $A$ is:

Match the terms in Column-I with their description in Column-II and choose the correct option :

Column I		Column II
(i)	Vitamin A	a	Beri-beri
(ii)	Vitamin C (Ascorbic acid)	b	Cheilosis
(iii)	Riboflavin	c	Xerophthalmia
(iv)	Thiamine	d	Scurvy

Sulphur (S)-containing amino acids from the following are:
(a) Isoleucine
(b) Cysteine
(c) Lysine
(d) Methionine
(e) Glutamic acid

Red ppt. by Benedict solution is?

L-isomer of tetrose X ($C_4H_8O_4$) gives positive Schiff’s test and has two chiral carbons. On acetylation, ‘X’ yields triacetate. ‘X’ undergoes following reactions

Chiral compound ‘X’ is

The number of electrons involved in the reduction of permanganate to manganese dioxide in acidic medium is _______

Oxidation number of Mo in Ammonophosphomolybdate

Which of following are reducing and oxidising agent respectively.

During the reaction of permanganate with thiosulphate, the change in oxidation of manganese occurs by value of 3. Identify which of the below medium will favour the reaction.

See the following chemical reaction: \[ \text{Cr}_2\text{O}_7^{2-} + \text{XH}^+ + \text{6Fe}^{2+} \rightarrow \text{YCr}^{3+} + \text{6Fe}^{3+} + \text{ZH}_2\text{O}. \] The sum of $X$, $Y$, and $Z$ is _____.

Consider the following reaction sequence: $[CaCl_2 + Na_2CO_3 → X+Y] → Z$

$H_2O_2$ behave like reducing agent in which of the following reactions:

Match List I with List II

Choose the correct answer from the options given below:

Compound A reacts with $NH _4 Cl$ and forms a compound B Compound B reacts with $H _2 O$ and excess of $CO _2$ to form compound $C$ which on passing through or reaction with saturated $NaCl$ solution forms sodium hydrogen carbonate Compound $A , B$ and $C$, are respectively

Which one among the following metals is the weakest reducing agent?

Compound A reacts with $NH _4 Cl$ and forms a compound B.

Compound B reacts with $H _2 O$ and excess of $CO _2$ to form compound $C$ which on passing through or reaction with saturated $NaCl$ solution forms sodium hydrogen carbonate Compound $A , B$ and $C$, are respectively.

Sum of $\pi$-bonds present in peroxodisulphuric acid and pyrosulphuric acid is___________

The total number of acidic oxides from the following list is: $NO , N _2 O , B _2 O _3, N _2 O _5$, $CO , SO _3, P _4 O _{10}$

Match List I with List II