Chemistry Questions and Answers

H $_2$ S + Cl $_2$ → 2HCl + S

  Please note: substance oxidized or reduced are always the reactants. So, one can easily cross out the two products.

  Reduction is

  1. Addition of hydrogen

  2. Removal of Oxygen

  3. Addition of Electron

  Oxidation is

  1. Removal of hydrogen

  2. Addition of hydrogen

  3. Removal of Electron

  From the question we can see that H was added to Cl in the product, thereby making hydrogen to be removed from S in the reactant hence S is oxidized as a result of the removal of hydrogen and Cl $_2$ has been reduced due to addition of hydrogen.

Cl $_2$ is reduced

The periodic number table is arranged in order of atoms increasing atomic number

Bacteria of the genus Propionibacterium produce propionic acid (Propanoic Acid) as the end-product of their anaerobic metabolism. This class of bacteria is commonly found in the stomach of ruminants and the sweat glands of humans, and their activity is partially responsible for the odour of both Swiss cheese and sweat.

The definition of enthalpy change is

  ΔH = ΔU + Pex(ΔV)

  The enthalpy change is zero because both terms on the right are zero in free expansion of an ideal gas.

  There is no external pressure in a free expansion, so P (ex) = 0. And the internal energy change, ΔU of free expansion in a closed system is zero since no inter molecular forces have to be overcome. The temperature remains constant and no heat is absorbed or released.

N$_{2(g)}$ + 3H$_{2(g)}$ ⇔ 2NH$_{3(g)}$ In the Haber process, the forward reaction is exothermic and the backward reaction is endothermic. If the temperature is decreased, the yield from the exothermic direction is increased i.e. the forward reaction is increased.