List of top Chemistry Questions

Identify the pair which is not correctly matched:
Polyacrylonitrile is used as a substitute for wool in making commercial fibres as acrilan. The structure of it is:

Match the following complexes with their number of unpaired electrons:

List-I (Complex) List-II (No. of unpaired electrons) 
A) \([\mathrm{MnCl}_6]^{3-}\) I) 5 
B) \([\mathrm{FeF}_6]^{3-}\) II) 2 
C) \([\mathrm{Mn(CN)}_6]^{3-}\) III) 0 
D) \([\mathrm{Co(C}_2\mathrm{O}_4)_3]^{3-}\) IV) 4 

Match the following molecules with their bond angles:

List-I (Molecule) List-II (Bond angle) 
A) \(\mathrm{NH}_3\) I) 102.2° 
B) \(\mathrm{O}_3\) II) 107.8° 
C) \(\mathrm{S}_6\) III) 93.6° 
D) \(\mathrm{PH}_3\) IV) 117° 
A liquid mixture of aniline and 'x' forms a non-ideal solution with negative deviation from Raoult's law. What is 'x'?
What are the mole fractions of glucose and water respectively, in 20% (w/w) aqueous glucose solution? (\(C = 12\,u\); \(O = 16\,u\); \(H = 1\,u\))
A compound consists of atoms A and B. The atoms of B form hcp lattice. The atoms of A occupy \(\frac{1}{3}\) rd of octahedral voids and \(\frac{1}{3}\) rd of tetrahedral voids. What is the molecular formula of the compound?
The correct sequence of reactions involved in the conversion of \(n\)-heptane to benzene is:
Electrolysis of aqueous solution of potassium acetate gives an alkane (x) and \({CO}_2\) (y) at anode. The volume ratio of these two gases \(x\) and \(y\) at STP is respectively:
Identify the herbicides from the following:
a) DDT b) Aldrin c) Sodium chlorate d) Nicotine e) Sodium arsenite
In which of the following set, both the substances have same hybridisation?

Consider the following statements: 
Statement-I: The products formed when diborane burns in air are \({B}_2{O}_3\), \({H}_2\), and \({O}_2\). 
Statement-II: Hybridization of boron atom in orthoboric acid is \(sp^2\). The correct answer is:

The \(E^\circ_{{M}^+_{(aq)}}/{M}_{(s)}\) is highest with negative sign for alkali metal 'x' and lowest with negative sign for alkali metal 'y'. In flame test, the characteristic colours of 'x' and 'y' are respectively:
Which of the following is not related to the removal of permanent hardness of water?
Which of the following aqueous solutions has highest pH? (Given \(\log 2 = 0.30\), \(\log 3 = 0.48\), \(\log 4 = 0.60\), \(\log 5 = 0.70\))

In acid medium dichromate oxidizes sulphite to sulphate as shown below. Identify correct statements about this balanced equation: 
\[ x {Cr}_2{O}_7^{2-} + y {SO}_3^{2-} + z {H}^+ \rightarrow a {Cr}^{3+} + b {SO}_4^{2-} + c {H}_2{O} \] Statements: 
I) Sum of \(x\) and \(y\) is (4) 
II) Sum of \(a\) and \(c\) is equal to \((3 + b)\). 
III) Sum of \(x\), \(y\), and \(z\) is 11.

At what temperature rms speed of \({SO}_3\) molecules is \(3.16 \times 10^2 \, {ms}^{-1}\)? (R = 8.314 J K\(^{-1}\) mol\(^{-1}\))
For one mole of an ideal gas, three isochors were obtained at \(V_1, V_2\) and \(V_3\) respectively. Their slopes are \(m_1, m_2\) and \(m_3\). If \(V_1<V_2<V_3\), then the correct relationship of slopes is:
The increasing order of covalent character of \(\mathrm{NaCl}\) (I), \(\mathrm{RbCl}\) (II), \(\mathrm{MgCl}_2\) (III), \(\mathrm{AlCl}_3\) (IV) is:
Observe the following molecules:
\({SO}_2, {H}_2{O}, {HgCl}_2, {BeCl}_2, {XeF}_2, {O}_3, {NO}_2, {PbCl}_2\).
The number of molecules with the same geometry as that of \({SnCl}_2\) is:
A spectral line of Lyman series of H-atom has a frequency of \(2.466 \times 10^{15} \, {s}^{-1}\). What is the transition responsible for this spectral line? (Rydberg constant \(R = 1.096 \times 10^7 \, {m}^{-1}\))
The total number of ions produced from the complex \( [Cr(NH_3)_6]Cl_3 \) in aqueous solution will be?
The disease caused by deficiency of pyridoxine is:
The ore, concentrated by froth floatation process is:
Which one of the following oxidizes manganous salt to permanganate in aqueous solution?