List of top Chemistry Questions

The largest number of molecules is in
The total number of electrons in one molecule of carbon dioxide is
When the same amount of zinc is treated separately with excess of sulphuric acid and excess of sodium hydroxide, the ratio of volumes of hydrogen evolved is
The compound which contains both ionic and covalent bonds is
The temporary hardness of water is due to calcium bicarbonate can be removed by adding
Ammonia gas can be dried by
How many moles are there in 18 grams of water ($ \text{H}_2\text{O} $)? (Atomic masses: H = 1, O = 16)
In a redox titration, 25 mL of 0.1 M KMnO$_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 molality of a solution prepared by dissolving 10 g of NaCl (\( M = 58.5 \, \text{g/mol} \)) in 500 g of water:
For a first-order reaction, the rate constant \( k \) is \( 1.386 \times 10^{-3} \, \text{s}^{-1} \). What is the half-life \( t_{1/2} \) of the reaction? (Use \( \ln 2 = 0.693 \))

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 'C' in the following reaction sequence? 

Which of the following has a maximum dipole moment?
The volume of 2 moles of an ideal gas at STP is:
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 5 moles of solute in 2 liters of solution?
Iii which of the following, the solubility of $AgCl$ will be minimum?
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 number of isomeric forms that are represented by C7H9N is:

What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)

Draw the Lewis structures for the following molecules and ions: \(H_2S\), \(SiCl_4\), \(BeF_2\), \(CO_3^{2-}\) , \(HCOOH\)

Describe the change in hybridisation (if any) of the Al atom in the following reaction.
\(AlCl_3+Cl^- \rightarrow AlCl_4^-\)
Write the resonance structures for SO3 , NO2 and NO3-
Identify the product formed in the following reaction:
aqueous sodium hydroxide (NaOH)
Assign oxidation numbers to the underlined elements in each of the following species: 
  1. \(NaH_2\underline PO_4\) 
  2. \(NaH\underline SO_4\) 
  3. \(H_4\underline P_2O_7\) 
  4. \(K_2\underline {Mn}O_4\) 
  5. \(Ca\underline O_2\) 
  6. \(Na\underline BH_4\) 
  7. \(H_2\underline S_2O_7\) 
  8. \(KAl(\underline SO_4)_2.12 H_2O\)