Total Questions: 50
Among the given metals, Lead is the least reactive.
A neutralisation reaction can be defined as a chemical reaction in which an acid and base quantitatively react together to form a salt and water as products.
• There is a combination of H⁺ ions and OH⁻ ions which form water.
• Example: HCl + NaOH → NaCl + H₂O
The successive members of a homologous series differ from each other by a -CH₂ group.
• The molecular mass of a -CH₂ group = 12 + 2 = 14.
• Hence, each successive homologue of a homologous series differ by a mass of 14 amu.
4Fe(s) + 3O₂(g) → 2Fe₂O₃(s)
Oxidation is the gain of oxygen. Reduction is the loss of oxygen.
• In the reaction 4Fe(s) + 3O₂(g) → 2Fe₂O₃(s), Iron (Fe) gains oxygen to form Ferric Oxide. So, it is oxidised.
The chemical name of marble is calcium carbonate (CaCO₃).• Marble, the hardest form of calcium carbonate, is a metamorphic rock.• It forms as a result of the recrystallization process of limestone, under conditions of high pressure and temperature.
When heated, baking soda produces sodium carbonate, carbon dioxide, and water.• Then due to the recrystallization of sodium carbonate, it gives out washing soda.
• Na₂CO₃ + 10H₂O → Na₂CO₃.10H₂O.
Magnesium(s) + Oxygen(g) → Magnesium oxide(s)
2Mg(s) + O₂(g) → 2MgO(s) is a combination reaction and an oxidation reaction where Mg is getting oxidized to form MgO.• Here, 2 magnesium atoms react with a molecule of oxygen-producing 2 molecules of the compound magnesium oxide-releasing some heat in the process.
Hydrogen was assigned a fixed position in the Mendeleev's periodic table.• Hydrogen had no fixed position in Mendeleev's Periodic Table.• This was because it resembles alkali metals by forming positive ions and resembles halogens by forming diatomic molecules.So, it was placed above both the groups and could not be given a fixed position.
Silicon (Si) and germanium (Ge) have the characteristics of both metals and non-metals.• Hence, they are semi-metals or metalloids.• The six commonly recognised metalloids are boron, silicon, germanium, arsenic, antimony, and tellurium.
Among Gold, Silver, Mercury and Copper, Gold is least reactive metal because of higher standard reduction potential value.Platinum is the most non-reactive metal.
