Chemistry Questions and Answers

In the electrochemical series, also known as the reactivity series, Sodium is placed at the top. The electrochemical series is a list of elements in the order of their standard electrode potentials (or redox potentials). Elements at the top of the series are more reactive and have a greater tendency to lose electrons and form positive ions.

Isotopes of an element have the same number of protons (which defines the element) but may have different numbers of neutrons. Since atoms are electrically neutral, the number of protons must equal the number of electrons in an atom.

In a molecule with three bonding pairs and no lone pairs around the central atom, the electron pairs arrange themselves in a trigonal planar geometry, with bond angles of approximately 120 degrees.

Chlorine gas exists in the gaseous state at room temperature (around 25 degrees Celsius) and standard pressure.

When sodium reacts with water, it undergoes a highly exothermic reaction, producing sodium hydroxide (NaOH) and hydrogen gas (H2).

One unique property of water is that it expands when it freezes. Most substances contract and become denser when they freeze, but water expands and becomes less dense. This is why ice floats on water.

The contact process is used for the industrial production of sulfuric acid (H2SO4), not any of the options provided. The process involves the oxidation of sulfur dioxide (SO2) to sulfur trioxide (SO3) which is then absorbed in sulfuric acid to form oleum (H2S2O7). The oleum is then diluted with water to form sulfuric acid.

According to Graham's law of diffusion, the ratio of the diffusion rates of two gases is the inverse of the square root of the ratio of their molar masses. Therefore:

Rate of A / Rate of B = √(Molar mass of B / Molar mass of A)
Rate of A / Rate of B = √(64 g/mol / 32 g/mol) = √2 = 1.41

So, the ratio of their diffusion rates is approximately 2:1.

NaCl, commonly known as sodium chloride or table salt, is an example of an electrovalent bond. Sodium (Na) donates one electron to chlorine (Cl), resulting in the formation of Na+ and Cl- ions, which are held together by the ionic bond.

If a blue litmus paper turns red when dipped into a solution, it indicates the presence of an acid in the solution. Acids turn blue litmus paper red.