Chemistry Questions and Answers

Aluminium hydroxide is not soluble in water because it is polymeric and it also has high lattice energy and therefore it is hard to break bonds in this compound. So, water cannot dissolve such types of compounds.

Al(OH)\(_3\) is not soluble in water

The method used to extract a metal from its ore depends upon the stability of its compound in the ore, which in turn depends upon the reactivity of the metal:

  • The oxides of very reactive metals, such as aluminum, form stable oxides and other compounds. A lot of energy is needed to reduce them to extract the metal.

  • The oxides of lesser reactive metals, such as iron, form less stable oxides and other compounds. Relatively little energy is needed to reduce them to extract the metal.

  So, the method of extraction of a metal from its ore depends on the metal's position in the reactivity series.

Recall from pH formula pH = -Log [H+]

  H2SO4 → 2H+ + SO42-

  2H+ → 2 X0.05 = 0.1

  pH= -Log [0.1] = 1

M = \(\frac{MmIT}{96500n}\)

  Where

  M=mass

  Mm = Molar mass = 64g/mol

  I = current = 1.6A

  T= Time  =1h r=3600s

  N= No of Charge = +2

  M = \(\frac{64x \times 1.6 \times 3600}{96500 \times 2}\)

  M=1.91g

Increasing temperature in exothermic reaction favors the left/reactant side and decreasing temperature will favor the right/product side.