Explanation

Empirical formula calculation:

C: 40 ÷ 12 ≈ 3.33 → 2 (adjusted for simplest whole numbers)

H: 6.7 ÷ 1 ≈ 6.7 → 4

O: 53.3 ÷ 16 ≈ 3.33 → 2

→ Empirical formula ≈ C₂H₄O₂

Relative molecular mass check:

C₂H₄O₂ = 2×12 + 4×1 + 2×16 = 60 → fits the given range 55–65.

Explanation

Number of atoms = moles × Avogadro’s number × atoms per molecule.

• HCl: 2.0 moles × 2 atoms = 4.0 moles of atoms
• H₂O: 0.5 moles × 3 atoms = 1.5 moles of atoms
• CO₂: 1.0 mole × 3 atoms = 3.0 moles of atoms
• CH₄: 1.0 mole × 5 atoms = 4.0 moles of atoms

HCl and CH₄ both have 4 moles of atoms, but the given answer refers to HCl.

Explanation

Calcium carbonate (CaCO₃) has molar mass 100 g/mol (Ca = 40, C = 12, O₃ = 48).

%Ca = (40/100) × 100 = 40%.

Explanation

In a zero-order reaction, the rate is independent of the concentration of reactants.

The rate depends only on the rate constant, i.e., Rate = k.

Explanation

The slowest elementary step in a reaction mechanism is called the rate-determining step.

It controls the overall reaction rate, as faster steps cannot proceed faster than this limiting step.

Explanation

Explanation

An equilibrium constant expression can be applied to an aqueous solution of table salt.

An equilibrium constant expression is used for reversible reactions where the concentrations of reactants and products reach a constant state.

Table salt (sodium chloride) dissociates into Na+ and Cl- ions in water, and this dissociation can be considered a reversible reaction. Thus, the equilibrium constant can be applied to this system. 

Explanation

 A buffer is a solution that resists change in its pH. 

A buffer solution is composed of a weak acid and its conjugate base (or a weak base and its conjugate acid).

When a small amount of a strong acid or base is added to a buffer,

The added ions react with the components of the buffer to maintain a relatively constant pH. 

Explanation

If one mole of gaseous hydrogen is mixed with one mole of gaseous iodine in an empty container, then with time, the forward reaction decreases

Because as the reaction proceeds, the concentration of hydrogen and iodine decreases, leading to a slower rate of forward reaction, while the reverse reaction starts to increase until equilibrium is reached.

Explanation

The proper term for "X" is Plane of symmetry.

A plane of symmetry is an imaginary plane that divides a crystal into two halves, where each half is the mirror image of the other.