List of top Chemistry Questions

Which of the following has covalent bond?
The conductivity of sodium chloride at 298 K has been determined at different concentrations and the results are given below: 
Concentration/M 0.001 0.010 0.020 0.050 0.100 
102  × κ/S m-1  1.237 11.85 23.15 55.53 106.74 
Calculate \(\land_m\) for all concentrations and draw a plot between \(\land_m\) and c ½. Find the value of  \(\land^0_m\).
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.
The volume of 2 moles of an ideal gas at STP is:
Define the following terms:
(i) Mole fraction 
(ii) Molality 
(iii) Molarity 
(iv) Mass percentage.

An ideal gas undergoes an isothermal process at 300 K. If the initial volume is 2 m\(^3\) and it doubles to 4 m\(^3\), what is the work done by the gas? (Take \(R = 8.31 \, \text{J/(mol.K)}\), and assume 1 mole of gas.)

Calculate the empirical formula of a compound containing 40% carbon, 6.7% hydrogen, and 53.3% oxygen by mass.
What is the molarity of a solution prepared by dissolving 5 moles of solute in 2 liters of solution?

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?

In a redox titration, 25 mL of 0.1 M KMnO$_4$ is required to completely react with oxalic acid in acidic medium. The volume of 0.2 M oxalic acid used is:
(Balanced reaction: \( 2\text{MnO}_4^- + 5\text{C}_2\text{O}_4^{2-} + 16\text{H}^+ \rightarrow 2\text{Mn}^{2+} + 10\text{CO}_2 + 8\text{H}_2\text{O} \))
Calculate the volume occupied by 4.4 g of CO$_2$ gas at 27°C and 1 atm pressure. (\( R = 0.0821 \, \text{L-atm/mol-K} \), Molar mass of CO$_2$ = 44 g/mol)
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 \(H_2O(l)\)}?