A Level H2 Chemistry 2021 Paper 3 Answers Official

Students needed to balance equations accurately, particularly when involving complex compounds or non-standard reactions.

Consists of 3 to 4 compulsory, long structured questions. These questions seamlessly blend different topics—such as connecting Energetics with Electrochemistry or Ideal Gases with Reaction Kinetics.

Answer: Increasing the pressure shifts the equilibrium position to the right (forward reaction) to decrease the pressure. This is because the forward reaction produces a fewer number of moles of gas (2 moles of NH₃) compared to the reactants (1 mole N₂ + 3 moles H₂ = 4 moles). Hence, the yield of ammonia increases. A Level H2 Chemistry 2021 Paper 3 Answers

: Identifying unknown compounds based on reaction products, such as an alkaline gas and an alkali formed from the reaction of a compound with water.

reacts completely with the conjugate base component of the buffer system: : Identifying unknown compounds based on reaction products,

b) A 2.0 g sample of ethanol (C2H5OH) is burned in a bomb calorimeter, releasing 29.7 kJ of energy. Calculate the molar enthalpy of combustion of ethanol. Answer:

Disclaimer: The suggestions provided are based on available 2021 school prelim/preliminary papers and student-compiled solutions. For official marking schemes, please refer to the SEAB-approved materials. Let me know which section you'd like to dive into! 2021 H2 Chemistry Paper 3 Solutions | PDF - Scribd Since the charges are the same

Answer: The lattice energy is proportional to $\fracq^+ q^-r^+ + r^-$. The $O^2-$ ion is smaller than the $S^2-$ ion. Therefore, the inter-ionic distance ($r^+ + r^-$) is smaller in MgO compared to MgS. Since the charges are the same, the electrostatic forces of attraction between the ions in MgO are stronger, resulting in a more exothermic (larger negative value) lattice energy.

Benzene is used as a starting material for the production of many chemicals, such as styrene, phenol, and aniline. Its derivatives are used in a wide range of applications, including pharmaceuticals, dyes, and plastics.