Explanation

Indicators are colored organic compounds that change color depending on the pH of the solution.

Common examples include litmus, phenolphthalein, and methyl orange.

Explanation

pOH is defined as the negative logarithm of the hydroxide ion concentration: pOH = -log[OH⁻].

It is used to measure the basicity of a solution, similar to how pH measures acidity.

Explanation

Ozonolysis is the reaction where ozone (O₃) breaks double bonds in alkenes to form ozonides.

This process is used to determine the position of double bonds in organic compounds.

Explanation

A nuclear reactor is a system designed to initiate and control a self-sustaining nuclear chain reaction.

It is mainly used for power generation, research, and production of isotopes.

Explanation

Alkenes are commonly known as Olefins due to their ability to form oily liquids when reacting with chlorine.

They are unsaturated hydrocarbons containing at least one carbon-carbon double bond (C=C).

Explanation

Gold can be beaten into extremely thin sheets (just a few atoms thick), ideal for alpha particle passage.

This thinness allowed alpha particles to pass through with minimal obstruction, helping observe atomic structure.

Explanation

At 170°C, ethanol undergoes acid-catalyzed dehydration to form ethene (C₂H₄).

Concentrated H₂SO₄ acts as a dehydrating agent, removing water from ethanol.

Explanation

In NH₄⁺, nitrogen has an oxidation state of –3 (typical for ammonia-like groups).

In NO₃⁻, nitrogen has an oxidation state of +5 due to its bonding with three oxygen atoms.

Explanation

Barium (Z = 56) → Electron configuration:

[Xe]6s²

Barium's electron distribution:

• K = 2
• L = 8
• M = 18
• N = 18 ⬅ Penultimate shell (4th shell / N-shell)
• O = 8 (valence shell)

The penultimate shell (N-shell) holds 18 electrons in Barium.

Explanation

Step 1: Calculate the molar mass of S8

The atomic mass of sulfur (S) is approximately 32 g/mol. The molar mass of S8 = 8 * 32 = 256 g/mol.

Step 2: Calculate the number of moles of S8

Number of moles = mass of S8 / molar mass of S8 = 64 g / 256 g/mol = 0.25 mol.

Step 3: Calculate the number of molecules of S8

Number of molecules = number of moles * Avogadro's number (NA) = 0.25 * NA.

Step 4: Calculate the number of sulfur atoms

Each molecule of S8 contains 8 sulfur atoms. Therefore, the total number of sulfur atoms = 8 * number of molecules = 8 * 0.25 * NA = 2 * NA = 2NA.