Explanation

In gas chromatography (GC), the mobile phase is a gas, such as helium, nitrogen, or argon, that carries the sample through the column.

The sample is vaporized and separated based on its affinity for the stationary phase, which is typically a solid or liquid coating on the column.

Explanation

The physical methods used to measure physical properties are called Gravimetric analysis methods.

This technique involves measuring the mass of a substance to determine its concentration or quantity.

Explanation

The prefix "hept" stands for 7 carbon atoms.

This is a Greek prefix used in chemistry to denote the number of carbon atoms in a molecule.

Here are some examples:

• Hex- means 6
• Hept- means 7
• Oct- means 8
• Non- means 9
• Dec- means 10

Explanation

The equivalent weight of an element is the mass of the element that reacts with one mole of electrons (or one mole of hydrogen atoms).

For aluminum (Al), the equivalent weight is 9 g.

Atomic weight of Al = 27 g/mol

Valency of Al = 3 (since Al forms Al3+ ions)

Equivalent weight = Atomic weight / Valency

= 27 g/mol / 3

= 9 g

So, 1 g equivalent weight of Al is 9 g!

Explanation

• The empirical formula of hydrogen peroxide (H2O2) is HO.
• The empirical formula is the simplest whole-number ratio of atoms of each element in a compound.
• In this case, the ratio of hydrogen to oxygen is 1:1, which is represented by the formula HO.

Explanation

Given:

- Length of string, L = 30 cm

- In 2nd harmonic, L = 3λ/4

Solving:

30 = (3/4)λ  

⇒ λ = (4 × 30) / 3 = 40 cm

Explanation

Cinnabar is the most common ore of mercury, and its chemical formula is HgS (mercury sulfide).

It has a bright red color and is used to extract mercury.

Explanation

The chemical formula for palmitic acid is C₁₆H₃₂O₂.

It is also known as hexadecanoic acid.

Palmitic acid is a saturated fatty acid, meaning it contains only single bonds between carbon atoms. 

Explanation

With an increase in the number of unpaired electrons, paramagnetism increases. 

Paramagnetism is directly related to the presence of unpaired electrons.

More unpaired electrons mean a stronger magnetic field, hence a greater degree of paramagnetism. 

Explanation

 The enthalpy change during the formation of one mole of a compound from its elements in their standard states is called standard heat of formation.