List of top Chemistry Questions

The structural formula of 2-methyl-2-butene is

How is the variability in oxidation states of transition metals different from that of the non-transition metals? Illustrate with examples.

Describe the preparation of potassium dichromate from iron chromite ore.  What is the effect of increasing pH on a solution of potassium dichromate?

Give the IUPAC names of the following compounds:

(i)CH3CH(Cl)CH(Br)CH3

(ii)CHF2CBrClF

(iii)ClCH2C≡CCH2Br

(iv)(CCl3)3CCl

(v)CH3C(p-ClC6H4)2CH(Br)CH3

(vi)(CH3)3CCH=CClC6H4I-p

A compound contains 40% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is its empirical formula?
(Atomic masses: C = 12, H = 1, O = 16)

Which of the following is an example of an addition reaction?

What is the \( n \)-factor of \(KMnO_{4}\) in acidic medium?

The enthalpy of combustion of methane is \(-890 \, \text{kJ/mol}\). What is the enthalpy change when 8 g of methane is burned?
(Molar mass = 16 g/mol)

What is the percentage of carbon in ethanol (\(C_{2}H_{5}OH\)) ? 
(Atomic masses: C = 12, H = 1, O = 16)

A gas occupies 500 mL at 1 atm pressure. What will be its volume at 2 atm, temperature constant?
Given:
\( E^\circ_{\text{Zn}^{2+}/\text{Zn}} = -0.76 \, \text{V} \)
\( E^\circ_{\text{Cu}^{2+}/\text{Cu}} = +0.34 \, \text{V} \)
What is the EMF of the galvanic cell:
\(\text{Zn} \mid \text{Zn}^{2+} \parallel \text{Cu}^{2+} \mid \text{Cu}\)?
Which metal is extracted by electrolytic reduction?
How will you bring about the following conversions?
  1. Ethanol to but-1-yne
  2. Ethane to bromoethene
  3. Propene to 1-nitropropane
  4. Toluene to benzyl alcohol
  5. Propene to propyne
  6. Ethanol to ethyl fluoride
  7. Bromomethane to propanone
  8. But-1-ene to but-2-ene
  9. 1-Chlorobutane to n-octane
  10. Benzene to biphenyl.
Define the following terms:
(i) Mole fraction 
(ii) Molality 
(iii) Molarity 
(iv) Mass percentage.

For the reaction \(N_2(g) + 3H_2(g) \rightleftharpoons 2\text{NH}_3(g)\) at 298 K, the enthalpy change \( \Delta H = -92.4 \, \text{kJ/mol} \). What happens to the equilibrium when temperature is increased?

What is the molarity of a solution prepared by dissolving 4 g of NaOH in 250 mL of solution? (Molar mass of NaOH = 40 g/mol)

The enthalpy change for the reaction
 \(2H_2(g) + O_2(g) → 2H_2O(l)\)
is -572 kJ/mol. What is the enthalpy change for the formation of 1 mole of \(H_2O(l)\)}?

Vapour pressure of water at 293 K is 17.535 mm Hg. Calculate the vapour pressure of water at 293 K when 25 g of glucose is dissolved in 450 g of water.
The mass of 60% HCl by mass required for the neutralisation of 10 L of 0.1 M NaOH is

Draw all the isomers (geometrical and optical) of: 
(i) \([CoCl_2(en)_2]^{+}\) 
(ii)\( [Co(NH_3)Cl(en)_2] ^{2+} \)
(iii)\( [Co(NH_3)_2Cl_2(en)]^{+}\)

$0.833$ mole of a carbohydrate with empirical formula $CH_{2}O$ , has $10\, g$ of hydrogen. Molecular formula of the carbohydrate is
Define the term solution. How many types of solutions are formed? Write briefly about each type with an example.

How would you account for the following: 

  1. Of the d4 species, Cr2+ is strongly reducing while manganese(III) is strongly oxidising. 
  2. Cobalt(II) is stable in aqueous solution but in the presence of complexing reagents it is easily oxidised. 
  3. The d1 configuration is very unstable in ions.

Comment on the statement that elements of the first transition series possess many properties different from those of heavier transition elements.

Which of the following is/are endothermic reaction(s)?