## anonymous 4 years ago Can anyone teach me mole concept .. please ?

1. anonymous

I am in a doubt from where should I start.. Firstly tell me what you know about Mole concept till now?? Don't worry just tell me what you know about this ??

2. anonymous

to be frank i dont know anything , this is my new chapter . the teacher taught something but nothing did enter my brain , my only hope is you now , teach my like how yu teach first grader .. please , having my test this wednesday !

3. anonymous

4. anonymous

See, to measure any quantity you will need a suitable measure for it.. Right??

5. anonymous

yes

6. anonymous

Say for example: You have 12 bananas.. So for simplicity or measuring it you say it is 1 dozen. 12 bananas = 1 Dozen So, here you have measured 12 bananas by saying 1 Dozen of bananas.. Getting ??

7. anonymous

yea .. getting it :)

8. anonymous

Now you know in even a small substance or quantity, there are very large number of atoms and molecules.. These atoms and molecules are very small so in even in a very small quantity they are present in very large amount.. Getting this ??

9. anonymous

yea got it !

10. anonymous

So, here If I want to measure these atoms and molecules I need a suitable measure for it too so that I can measure or define these large numbers of atoms or molecules with ease.. So for that we need Mole Concept.. Got this??

11. anonymous

yea .. thanks water , you dont teach lyk how my teache did :D

12. anonymous

Insulting me?? Ha ha ha.. Never mind..

13. anonymous

Wanna proceed further ??

14. anonymous

hey am nt insulting ,i meant to say you were teaching very wel and nothing like how my teacher did .. of course .. please proceed !

15. anonymous

I was just kidding @ashna

16. anonymous

:)

17. anonymous

You should remember this : Basically, we use idea of mole or Mole concept to count at the Microscopic Level.. By Microscopic Level, we mean very small particles like atoms, molecules, electrons, ions etc.. These are counted in Microscopic Levels. Getting the wordings here ??

18. anonymous

*to count entities..

19. anonymous

yea getting :)

20. anonymous

So now we will define What Mole is..

21. anonymous

okay !

22. anonymous

This is the book definition of Mole.. you can check in your book..

23. anonymous

one mole = 6.023 * 10^23 molecules ?

24. anonymous

Yes but its the value.. I am talking about definition..

25. anonymous

oh okay .. !

26. anonymous

$$\color{blue}{\text{Mole}}:$$ One Mole is the amount of a Substance that contains as many particles (entities) as there are atoms in exactly $$12 \;grams$$ of the $$^{12}C$$ isotope.

27. anonymous

This is book definition.. I explain you best to my knowledge..

28. anonymous

There $$C$$ is Carbon..

29. anonymous

okay !

30. anonymous

@ashna , do you know for measuring any quantity we keep some standards for measuring any quantity..

31. anonymous

like fore mass , kg ?

32. anonymous

Close to it.. I explain you.. For mass it is kg.. But we should make some standards which will define what kg is.. We first make standards for kg so that we can say this much amount is kg.. So that whole world can follow the same..

33. anonymous

yeah okay !

34. anonymous

That is called Standardization of something. For length it is meters of course.. but we will standardize the meter.. Suppose this will create problem if I say 100cm is 1 meter and you will say no 200 cm is 1 meter.. In that case we will fight.. Right ??

35. anonymous

yeah .. we will :P

36. anonymous

So to standardize the Mole we measure all the atoms in 12 grams of Carbon and the result we got from that we call it as one mole..

37. anonymous

wow .. i understood :D

38. anonymous

then .. ?

39. anonymous

Okay..

40. anonymous

Now we will find its value and define Avagadro's Number.. Heard the name ??

41. anonymous

yeah !

42. anonymous

I am just telling you but if you want then you can leave it too: By using a device called "Mass Spectrometer" (used to find Mass) physicists calculate the MASS OF ONE ATOM OF CARBON ($$^{12}C$$) to be: $\large 1.992648 \times 10^{-23} \; g$

43. anonymous

Do you know the Atomic Mass of Carbon ??

44. anonymous

oh .. never heard of that , ty :)

45. anonymous

12 ?

46. anonymous

Yep..

47. anonymous

okay !

48. anonymous

then ?

49. anonymous

So we calculate the value of mole by using: $Number \; \; of \; \; Atoms = \frac{Mass}{Mass \; of \; One \; Atom}$

50. anonymous

You can say 1 Mole also in place of Number Of Atoms.. $\large 1 \; Mole = \frac{12}{1.992648 \times 10^{-23}}$

51. anonymous

understood !

52. anonymous

You can say 1 Mole also in place of Number Of Atoms.. $\large 1 \; Mole = \frac{12}{1.992648 \times 10^{-23}}$ $\large 1 Mole = 6.023 \times 10^{23}$

53. anonymous

okay .. can you tell me the difference between mole and molecules ?

54. anonymous

Mole is a measuring quantity.. Molecule is like formed by atoms.. $O_2$ this is molecule.

55. anonymous

okay !

56. anonymous

This is called Oxygen Molecule..

57. anonymous

Actually mole will contains molecules. Suppose 1 mole will contains 6.023*10^{23} molecules of Oxygen..

58. anonymous

*will contain..

59. anonymous

so you mean 1 C and 1 O contains same number of molecules ? or is it the same for all elements ?

60. anonymous

Just similar to : 1 Dozen will contain 12 Bananas. 1 Mole will contain 6.023*10^{23} molecules..

61. anonymous

okay !

62. anonymous

Yes coming to your question right now..

63. anonymous

See if you are talking about atoms then 6.023*10^{23} atoms.. If you are talking about molecules then 6.023*10^{23} molecules.. I give you example have patience..

64. anonymous

okay :)

65. anonymous

1 Mole of Hydrogen Atoms = $$6.023 \times 10^{23}$$ hydrogen atoms. 1 Mole of Water Molecules = $$6.023 \times 10^{23}$$ water molecules..

66. anonymous

okay

67. anonymous

1 Mole of Carbon Atoms = $$6.023 \times 10^{23}$$ Carbon atoms. 1 Mole of Oxygen Atoms = $$6.023 \times 10^{23}$$ Oxygen atoms..

68. anonymous

yeah .. now i can understand :)

69. anonymous

70. anonymous

is that tough ?

71. anonymous

1 Mol is given other name as "Avagadro's Constant" So: $$6.023 \times 10^{23}$$ is the value for :Avagadro's Constant".. Avagadro's Constant is denoted by $$N_A$$; So: $N_A = 6.023 \times 10^{23}$

72. anonymous

Is this tough?? Ha ha ha

73. anonymous

why laughing ?

74. anonymous

My habbit..

75. anonymous

you got brains .. and my brains have just started developing .. that too after entering into open study !

76. anonymous

No I did not mean that @ashna ..

77. anonymous

i dont like chem , phy or math .. am only into literature !

78. anonymous

oh god .. am not making you feel or anything .. am just talking naturally .. am sorry if you felt for it !

79. anonymous

Literature?? Great.. Here Literature section is also there. You can spend your time there also..

80. anonymous

i know :)

81. anonymous

Na means ?

82. anonymous

It is denotion for Avagadro's constant..

83. anonymous

I mean you can represent Avagadro's Number or constant as: $Avagadro's \; Constant = N_A = 1 Mole = 6.023 \times 10^{23}$

84. anonymous

okay .. and may i know if it is 10^22 or 10^23 or both ?

85. anonymous

Not both: only 23..

86. anonymous

I am using 23 everywhere..

87. anonymous

$\huge 1 Mole = 6.023 \times 10^{23}$

88. anonymous

scroll up and see what you wrote for avagadros constant 1

89. anonymous

1 Mol is given other name as "Avagadro's Constant" So: $$6.023 \times 10^{23}$$ is the value for :Avagadro's Constant".. Avagadro's Constant is denoted by $$N_A$$; So: $$N_A=6.023×10^{23}$$ Here ??

90. anonymous

yea ..

91. anonymous

is it 22 for avagadro's constant ?

92. anonymous

Where I have written 22 then ??

93. anonymous

No..

94. anonymous

It has the same values as 1 Mole has...

95. anonymous

*10^23 ? is what you have written ?

96. anonymous

looks like 22 to me .. its okay , next week ll hav eye check up .. you continue :)

97. anonymous

Yes.. Right click on that then select Show Math As and then text commands if you want to confirm..

98. anonymous

its okay .. i trust you ;)

99. anonymous

What I can explain more in this ?

100. anonymous

Do you know about Molar Mass ??

101. anonymous

teach me how to do the sums !

102. anonymous

Ha ha ha... My weakest part..

103. anonymous

Do you know what is molar mass ??

104. anonymous

what is molar mass .. ?

105. anonymous

some problem with my net connection .. that's why i seemed offline sorry !

106. anonymous

am sorry again !

107. anonymous

See @ashna I am helping you and I had studied these 5 years ago I am not good at these but I am seeing what I can do this for you in this. Don't say sorry it is okay..

108. anonymous

And we have other members too so don't worry we are on safe side..

109. anonymous

okay .. but i prefer you .. u've been the one who has been helping me from the begining in OS !

110. anonymous

what is molar mass ?

111. anonymous

Molar Mass is: See once you have found 1 Mole of any substance then Mass of that 1 Mole of substance in grams in called Molar Mass..

112. anonymous

okay .. partly understood .. examples in stock ?

113. anonymous

This is my wording not according to the book: According to the book definition: Molar Mass: The Mass of one Mole of a substance in grams is called Molar Mass.. I give you example..

114. anonymous

okay !

115. anonymous

Can you tell me molecular mass of Water ??

116. anonymous

i dont know !

117. anonymous

$$H_2O = 2 \times 1 + 16 = 18$$

118. anonymous

oh okay !

119. anonymous

there are two H: H has mass equal to 1. So 2 H's will have 2 there is one O: oxygen has 16 as its mass: 16 2 + 16 = 18 Have you studied about molecular mass ?/

120. anonymous

if this is called molecular mass.. then yes , some basics in my 8th !

121. anonymous

am not sure with the names !

122. anonymous

Remember : This is called Molecular Mass..

123. anonymous

okay !

124. anonymous

you ask me the molecular mass of something.. let me try !

125. anonymous

Then Molar Mass is simple just very simple: Molar Mass = 18 grams..

126. anonymous

oh .. just write it in terms of g ?

127. anonymous

Find the molecular mass of Sodium Chloride (Salt). Do you know symbolically what is it ??

128. anonymous

nacl ?

129. anonymous

Yes can you find its molecular mass ?/

130. anonymous

let me try !

131. anonymous

I am attaching here some flash file hope you will like it..

132. anonymous

atomic mass of Na is 23 atomic mass of Cl is 35.5 add them both ?

133. anonymous

I will send you by other means it will take time to upload here.. Yes add them both..

134. anonymous

okay !

135. anonymous

58.5

136. anonymous

molar mass 58.5g ?

137. anonymous

yep..

138. anonymous

:)

139. anonymous

Can you give me the question on mole concept so that I can explain you how to do it.. I am unable in finding it..

140. anonymous

Wait. This has gone long. Start a new post..

141. anonymous

okay :)

142. anonymous

I mean to say that can we start a new post @ashna

143. anonymous

yea okay !

144. anonymous

Medal for finding molecular mass of NaCl..

145. anonymous

lol .. thanks :)