Question

Today's Question :

a) What is Mole Concept ? Give examples .
b) Calculate the number of moles for the following :-

• 52 gram of Helium ( Finding mole from mass)
• 12.044×10²³ number of Helium atoms
( finding number of moles from particles )

Thanks!​

Answer 1

$\huge\underline\mathfrak\blue{Mole\:\:Concept:-}$

The word mole was introduced by Wilhelm Ostwald. Mole is a latin word which means a pile or heap. A mole is defined as the amount of any chemical substance that contains as many elementary entities.

Example : Atoms, ions, molecules, Electrons or Protons .

__________________________

a. Solⁿ

Given,

• Mass = 52 g
• Molar Mass = 4 g
• No. of moles = ?

$\therefore \sf \: Number \: of \: moles = \frac{given \: mass}{gram \: molar \: mass} \\ \\ \longrightarrow \sf \: h = \cancel \frac{52}{4} \: \\ \\ \longrightarrow \sf \: h = 13$

_____________

b. Solⁿ

Given ,

• No. of particles = 12.044×10²³
• Avagadro's Number = 6.022×10²³
• No. of moles = ?

$\qquad \sf \: n = \frac{np}{no} \\ \\ \longrightarrow \sf \: \frac{12.044 \times {10}^{23} }{6.022 \times {10}^{23} } \\ \\ \longrightarrow \sf \: n = 2$