Chemistry Assignment Help >> General Chemistry >> Mole Concept Assignment Help

MOLE CONCEPT

 

For counting of articles, units like dozen or score is commonly used. Similarly in chemistry 'mole' is the counting unit for chemical entities. The amount of substance containing Avoqadro's number (6.023 x 10²³) atom, molecule, ions, electrons and protons, i.e.

(i) Number of moles of molecule = (Weight in gram)/(Molecular weight)

(ii) Number of moles of atoms = (Weight in gram)/(Atomic weight)

(iii) Number of moles of gases =(Volume at NTP)/(Standard molar vlaume (22.4 L) )

(iv) Number of milli moles = Molarity x Volume in mL

(v) For a compound P_x O_y

x moles of Q = y moles of P

(vi) (Number of entities)/(Avogadro^' number (6.023× 10 ²³ ) ) =Number of moles

Illustration 2: 44.8 litre of CO₂ at STP is obtained by heating x gm of pure CaCO₃. x is

(A) 100 g
(B) 200 g
(C) 50 g
(D) 44.8 g



1 mol of CO₂ is obtained from 1 mole of CaCO₃ 22.4 litre of gas at STP = 0 1 mol of gas 44.8 litre of gas at STP = 2 mol of gas Hence, 2 mole of CO₂ is obtained from 2 mole of CaCO₃ i.e., 2 x 100 = 200 gm of CaCO₃

(a) Law of isomorphism: Isomorphism substances form crystal which have same structure. Thus both the cation and anion of isomorphous substance have the same valency.

(b) Chemical formulae of a compound can be found out by the following steps:

(i) The percentage composition of compound is determined.

(ii) Then the percentage of each element is divided by the atomic mass and then a molar ratio of each element is obtained.

(iii) This molar ratio is divided by a minimum value to get the simplest ratio and an empirical formula is obtained.

(iv) Finally by comparing the molecular mass or vapour density of this empirical formulae to that of actual molecule its molecular formulae is obtained.

Email Based Assignment Help – Homework Help

We at ExpertsMind offer email based assignment help, homework help and project help service in general chemistry. We provide online solutions for any grade level from high school to college level or university level. Why ExpertsMind? We commit only if our expert commits to deliver solutions by due date with detailed answers. Our motto is to spread quality of education across the world. From last few years we have excelled in assignment help filed due to our quality of service. We help students till the end when they are fully satisfied with work, without any additional charges. That why we have gained faith of students.

Struggling with chemistry homework – assignment? Get solutions from live online chemistry experts at [email protected] or submit your homework here the form given below. Our instant tutors analyze your work and revert back with price quote which will be economical in student's point of view.