<u>Explanation:</u>
Molecular formula is the chemical formula which depicts the actual number of atoms of each element present in the compound.
Empirical formula is the simplest chemical formula which depicts the whole number of atoms of each element present in the compound.
In both the formulas, the nature of atoms remains the same but the number differs.
For Example: The molecular formula of oxalic acid is
but the empirical formula of oxalic acid is 
To calculate the molecular formula, we need to find the valency which is multiplied by each element to get the molecular formula.
The equation used to calculate the valency is:

The empirical mass can be calculated from empirical formula and molar mass must be known.
Answer:
The balanced chemical equation for this reaction is:
2HCl (aq) + FeS (s) -----> FeCl2 (aq) + H2S (g)
Explanation:
Answer:
The right solution is "
".
Explanation:
As we know,
1 mole electron = 
Total energy = 
= 
For single electron,
The amount of energy will be:
= 
= 
Answer:
4 moles of neon
Explanation:
Given data:
Number of moles of neon = ?
Number of atoms of neon = 2.4×10²⁴ atoms
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
For given neon atoms:
1 mol = 6.022 × 10²³ atoms
2.4×10²⁴ atoms × 1 mol / 6.022 × 10²³ atoms
0.4×10¹ mol = 4 mol
Not 100% sure if its right.
When an object covers equal distances in equal amounts of time, it is moving at a constant speed.