Explanation

Reaction: CaCO3 + 2HCl -> CaCl2 + CO2 + H2O

Given:

CaCO3 = 50g

Actual CO2 = 14.52g

Step 1: Molar mass of CaCO3 = 100 g/mol

Moles of CaCO3 = 50 / 100 = 0.5 mole

Step 2: 1 mole CaCO3 gives 1 mole CO2

So 0.5 mole CaCO3 gives 0.5 mole CO2

Step 3: Molar mass of CO2 = 44 g/mol

Theoretical yield of CO2 = 0.5 x 44 = 22g

Step 4: Percentage yield = (Actual / Theoretical) x 100

= (14.52 / 22) x 100

= 66%

Theoretical yield = 22g

Percentage yield = 66%

Last verified on 25-10-2026

Explanation

• According to Le Chatelier’s principle, adding nitrogen increases the concentration of a reactant, causing the equilibrium to shift to the right.
• The forward reaction consumes nitrogen and hydrogen to produce ammonia (NH₃).
• Therefore, adding more nitrogen increases the amount of ammonia produced as the system reaches a new equilibrium.

Last verified on 25-10-2026

Explanation

• A basic buffer solution consists of a weak base and its conjugate acid.
• It resists changes in pH when small amounts of acid or base are added.
• Ammonia (NH₃) is a weak base.
• When hydrochloric acid (HCl) reacts with excess ammonia, it forms ammonium chloride (NH₄Cl), leaving some unreacted NH₃.
• The mixture contains a weak base (NH₃) and its conjugate acid (NH₄⁺), making it a basic buffer solution.

Last verified on 25-10-2026

Explanation

• A catalyst increases the rate of a chemical reaction by providing an alternative reaction pathway with lower activation energy.
• Activation energy is the minimum energy required for reactants to start a chemical reaction.
• Lower activation energy allows more particles to react successfully in a given time.

Last verified on 25-10-2026

Explanation

• The compound CH₃CH=CH–C≡CH contains five carbon atoms, so the parent name is “penta.”
• Numbering starts from the end nearest the triple bond, giving the triple bond position 1 and the double bond position 3.
• The correct IUPAC name is pent-3-en-1-yne.

Last verified on 25-10-2026

Explanation

• Density is the mass per unit volume of a substance.
• Density is calculated by dividing the mass of a substance by its volume.
• The SI unit of density is kilogram per cubic metre (kg/m³).

Last verified on 25-10-2026

Explanation

• In this reaction, the reactant side has 4 moles of gas (3 + 1), while the product side has 3 moles of gas (2 + 1).
• Since the product side has fewer moles of gas than the reactant side, the value of Δn is negative.
• When Δn is negative, Kp is less than Kc under normal conditions.

Last verified on 25-10-2026

Explanation

• Naphthalene is aromatic.
• Because it has a conjugated ring system containing 10 π electrons and follows Hückel’s rule of 4n+2 π electrons.
• 1-Methylindole is aromatic.
• Because its fused ring system has continuous conjugation with 10 π electrons, including the contribution of the nitrogen lone pair.

Last verified on 25-10-2026

Explanation

• The forward reaction is exothermic because ΔH = −94 kJ/mol, meaning heat is released during the formation of SO₃.
• Increasing temperature shifts the equilibrium towards SO₂ and O₂, reducing the equilibrium constant Kp.
• According to Le Chatelier’s principle, increasing pressure shifts the equilibrium towards SO₃ because the product side has fewer moles of gas (2 moles) than the reactant side (3 moles).
• A catalyst speeds up both forward and reverse reactions equally.
• It does not change the equilibrium constant or the equilibrium yield of SO₃.

Last verified on 25-10-2026

Explanation

• Metals above hydrogen in the electrochemical series generally have more negative standard reduction potentials and tend to lose electrons more readily than hydrogen.
• Hydrogen acts as the cathode when it gains electrons and undergoes reduction in a galvanic cell where such a metal acts as the anode.
• The metal above hydrogen acts as the anode and as the reducing agent because it loses electrons and reduces another substance.

Last verified on 25-10-2026