Acid, Base And Salt

When ammonium hydroxide (NH4OH) reacts with sulfuric acid (H2SO4), it forms water (H2O) and a salt. The salt formed in this reaction is (NH4)2SO4, also known as ammonium sulfate.

When 10 ml of NaOH solution is completely neutralized by 8 ml of HCl solution, it means that the two solutions have a 1:1 ratio of their respective moles. Therefore, the number of moles of NaOH in 10 ml is equal to the number of moles of HCl in 8 ml.

If we take 20 ml of the same NaOH solution, the number of moles of NaOH will be twice as much as before. To completely neutralize this amount of NaOH, we would need an equal number of moles of HCl. Since the ratio of moles is 1:1, we would need 16 ml of HCl solution (twice the amount of 8 ml) to neutralize the 20 ml of NaOH solution.

Glucose solution will not conduct electricity and therefore the bulb will not glow when electric current is passed through it. This is because glucose is a non-electrolyte, meaning it does not dissociate into ions in solution. In contrast, tap water, hydrochloric acid, and dilute sulphuric acid are all electrolytes and will conduct electricity, allowing the bulb to glow when current is passed through them.

When a small amount of acid is added to water, two phenomena occur. Firstly, ionisation takes place where the acid molecules dissociate into ions in the water. This leads to the formation of hydronium ions (H3O+) and anions. Secondly, dilution occurs as the acid is mixed with water, resulting in a decrease in the concentration of the acid solution. Therefore, the correct answer is (i) and (iii).

When HCl (g) is passed through water, it ionizes in the solution, meaning it breaks apart into ions. This is because HCl is a strong acid and readily dissociates in water to form H+ ions. Additionally, it forms hydronium ions (H3O+) in the solution due to the combination of the H+ ions with water molecules. Therefore, the correct answer is (ii) and (iv).

The correct answer is (ii) only. This is because NaOH is a strong base and when it dissolves in water, it dissociates into ions (Na+ and OH-) which can conduct electricity. Therefore, the bulb will glow due to the presence of ions in the electrolyte. The acidity of the electrolyte does not affect the conductivity in this case.

When HCl(aq) is exactly neutralized by NaOH(aq), it forms water and a salt, NaCl. In this reaction, one H+ ion from HCl combines with one OH- ion from NaOH to form water. Since the reaction is stoichiometrically balanced, the number of H+ ions is equal to the number of OH- ions. Therefore, the hydrogen ion concentration in the resulting mixture is always equal to the concentration of the hydroxide ions.

The correct answer is "Absorb water from air". Anhydrous calcium chloride is a commonly used desiccant, meaning it has the ability to absorb moisture from the surrounding environment. By placing it in a guard tube, it can effectively remove water vapor from the air, preventing any moisture from reaching the desired substance or environment. This is particularly useful in applications where moisture can cause damage or interfere with processes, such as in laboratories or storage of sensitive materials.

Wasp is the correct answer because unlike honey bees and ants, wasps do not inject acidic liquid into the skin through their sting. Instead, wasps inject a venomous substance that causes pain and irritation. Nettle leaf hair is not a living organism and therefore does not have the ability to inject any substances into the skin.

The given correct answer is "All metal oxides react with water to give salt and acid." This statement is not correct because metal oxides react with water to form metal hydroxides, not salts and acids.

The correct representation of the reaction occurring during the chloralkali process is 2NaCl (aq) + 2H2O (l) → 2NaOH (aq) + Cl2(g) + H2(g). This is because the reactants, sodium chloride (NaCl) and water (H2O), are both in aqueous form, indicating that they are dissolved in water. The products, sodium hydroxide (NaOH), chlorine gas (Cl2), and hydrogen gas (H2), are also indicated with their respective states of matter.

The given equation represents a neutralization reaction. In a neutralization reaction, an acid (H+) reacts with a base (OH-) to form water (H2O). This type of reaction typically occurs when an acidic and basic solution are mixed together, resulting in the formation of a neutral solution.

The correct procedure is to add 50 mL of 12 M HCl to 50 mL of water while stirring the mixture steadily. This is because when preparing a solution with a lower concentration, it is recommended to add the concentrated solution (12 M HCl) to the solvent (water) to avoid any potential splashing or spilling. By adding the concentrated solution slowly to the solvent, it allows for better mixing and ensures a more accurate and controlled dilution process.

The molarity of the acid solution can be calculated using the formula: Molarity of acid x Volume of acid = Molarity of base x Volume of base. Plugging in the given values, we get: Molarity of acid x 14.4 mL = 0.20 M x 22.4 mL. Solving for the molarity of acid, we find that it is 0.31 M.

The pH scale measures the acidity or basicity of a solution. A lower pH value indicates a higher acidity, while a higher pH value indicates a higher basicity. Therefore, statement (i) is correct because a higher pH value corresponds to a weaker acid. On the other hand, statement (iv) is correct because a lower pH value corresponds to a stronger base.