## ashna Group Title mole concept ! 2 years ago 2 years ago

1. ashna

@waterineyes back here :)

2. waterineyes

3. ashna

yea .. okay !

4. ashna

Calculate the mass of the following : (a) 0.5 mole of CO2. (b) 6.02 * 10^21 molecules of O2. (c) 1 * 10^23 molecules of H2S. (d) 56.8 L of SO2. (e) 1.5 mole of H2SO4.

5. waterineyes

I had said to write question here not questions here .. Ha ha ha.. Kidding..

6. ashna

i don't understand .. what did you want me to do actually ?

7. waterineyes

question means one question. questions means more than one questions.. Leave it.

8. ashna

oh i din see the < S > !

9. ashna

its one question my teacher gave !

10. ashna

there are many questions like this .. and water will solve everything :p

11. ashna

i hope so !

12. waterineyes

Ha ha ha..

13. ashna

:)

14. ashna

so you know this ?

15. waterineyes

Yes...

16. ashna

so teach !

17. waterineyes

For fist part: Find the molecular mass of $$CO_2$$..

18. waterineyes

*first..

19. ashna

molecular mass , mass and molar mass excluding the ( g ) all the same ?

20. waterineyes

I will say not to go this way..

21. ashna

then ?

22. waterineyes

See now you have studied What is Molar Mass.. Molar mass is mass of 1 mole of any substance. If that substance is CO2 then: Molar Mass is mass of 1 mole of CO2 So here basically you have to find Molar Mass.. For getting molar mass you will find the molecular mass of CO2 first same as you did for NaCl..

23. ashna

yeah okay .. so in the question we are asked to find the mass right ?

24. waterineyes

For atoms: we have atomic mass. For molecules we have molecular mass..

25. ashna

okay !

26. waterineyes

Yes.. Molar mass is nothing but mass only. Molar Mass is "Mass" of 1 mole of a substance in grams..

27. ashna

okay :)

28. ashna

so how to do (a) ?

29. ashna

mass of CO2 is 44 g ?

30. waterineyes

31. waterineyes

According to the definition of molar mass: Molar mass is mass of 1 mole right ??

32. ashna

yeah !

33. waterineyes

But you have to find for 0.5 mole.. This you got mass for 1 mole.. can you find? for 1 mole it is 44g for 0.5 or half it will be ??

34. ashna

0.5 * 44 / 1 ?

35. ashna

right ?

36. waterineyes

Yep..

37. ashna

okay :)

38. waterineyes

Think logically also.. For 1 it is 44g for half that is 0.5 is nothing but half of 1: for 0.5 it will be 44/2 = 22g. Getting ??

39. ashna

partially !

40. ashna

yea yea .. on second thinking i understood !

41. ashna

i forgot half of 1 is 0.5 !

42. waterineyes

0.5 is 1/2 no ??

43. ashna

yea i got it !

44. waterineyes

This solves first one.. Getting ??

45. ashna

dont laugh !

46. ashna

yeah :)

47. waterineyes

Ha ha ha ha.. Not I am not.. Ha ha ha..

48. ashna

lol yu are !

49. ashna

okay .. best medicine .. so laugh !

50. waterineyes

e> part is same.. Can you do that ??

51. ashna

let me try !

52. waterineyes

53. ashna

mass of 6.023 * 10^23 molecules of O2 = 32 mass of 6.02 * 10^21 molecules of O2 = x cross multiply ?

54. waterineyes

Go for last part.. e) part

55. ashna

okay !

56. waterineyes

This I tell you later on..

57. ashna

okay !

58. waterineyes

e part is same as a part. Just try that so that you will completely get it..

59. ashna

mass of 1 mole of CO2 = 44 g mass of 1.5 mole of CO2 = ? 44 * 1.5 / 1 = 66 g

60. ashna

@waterineyes

61. ashna

wrong ?

62. waterineyes

Yes concept is right..

63. waterineyes

Dear there is H2SO4 not CO2...

64. ashna

oh .. sorry !

65. ashna

okay let me do with H2SO4

66. waterineyes

Do the same for H2SO4..

67. waterineyes

I am in no hurry take your time..

68. waterineyes

Atomic Mass of H is : 1 Atomic Mass of S is : 28 Atomic Mass of O is : 16..

69. ashna

mass of 1 mole of H2SO4 = 98 g mass of 1.5 mole of H2SO4 = x = 98 * 1.5 / 1 = 147 g

70. ashna

atomic mass of s = 32 or 28 ?

71. ashna

@waterineyes there ?

72. waterineyes

I think you are right..

73. waterineyes

My mistake : Atomic Mass of Sulphur is 32..

74. ashna

okay !

75. waterineyes

Yes you have done that correctly: 98 + 49 = 147 g...

76. ashna

okay .. :)

77. waterineyes

Now we will do second part b)..

78. ashna

okay !

79. ashna

but i did that before right ?

80. ashna

is that wrong ?

81. waterineyes

Yes somewhat wrong..

82. ashna

okay .. so teach me :)

83. waterineyes

Sere have you remembered this: $1 Mole (oxygen) = 6.023 \times 10^{23} \; Oxygen \; \; Molecules$

84. ashna

okay

85. ashna

then .. how to do ? are you trying ?

86. waterineyes

Oh really very sorry.. You were doing it right

87. ashna

really ?

88. waterineyes

$6.023 \times 10^{23} \implies 32g$ $1 \implies \frac{32}{6.023 \times 10^{23}}$ $6.023 \times 10^{21} \implies \frac{32}{6.023 \times 10^{232}} \times 6.023 \times 10^{21} = ??$

89. waterineyes

Oh sorry there is mistake in denominator there power of 10 is 23 and not 232..

90. ashna

okay ..

91. waterineyes

There is mistake in denominator 10 has power 23 and not 232..

92. ashna

yeah you did mention it above !

93. ashna

so 32/100 = 0.32g ?

94. waterineyes

Yes you were going right @ashna Do it in your way if you did not understand my way..

95. ashna

no both seems the same .. i can understand :)

96. waterineyes

Yep you are right..

97. waterineyes

Now c part is same as b..

98. waterineyes

And there is H2S not O2. Ha ha ha.. Just kidding..

99. ashna

mass of 6.02*10^23 molecules of H2S = 34g mass of 1*10^23 molecules of H2S = x 34 * 1*10^23 / 6.02 *10^23 = 34 / 6.02 = 5.6 g

100. ashna

yea this time my eyes are wide :P

101. ashna

correct ?

102. waterineyes

Ha ha ha.. Yes you are right.. Now tell me what is L there with 56.8 I am not getting that..

103. waterineyes

In part D..

104. ashna

liter or litre not sure with the spelling .. !

105. waterineyes

Do you have answers with you for all of these??

106. ashna

not for everything !

107. waterineyes

or have your teacher given example of How for Liters we find the mass ??

108. ashna

yes .. you want that ?

109. waterineyes

yes if you can..

110. ashna

i guess the teacher has done this in class !

111. ashna

let me check !

112. waterineyes

okay..

113. ashna

okay she's written something like 22.4 L .. What is that ?

114. waterineyes

I think I am getting that 22.4 part..

115. ashna

okay !

116. waterineyes

Can you wait for just few minutes. I am having breakfast now.. Till then check this: http://www.ausetute.com.au/moledefs.html

117. waterineyes

There check: Ideal Gas Volumes Part..

118. waterineyes

Getting @ashna ..

119. ashna

YES

120. waterineyes

An ideal gas has Volume = 22.4 L at STP..

121. ashna

okay

122. waterineyes

So: 1 Mole of SO2 = 22.4 L 1L = 64/22.4 56.8 L = 64/22.4 * (56.8? Right ??

123. ashna

yes

124. waterineyes

Can you do the solvation ??

125. ashna

okay

126. waterineyes

Understood ?? How to find all ??

127. ashna

162.28 ?

128. waterineyes

Yep..

129. ashna

thank you :)

130. waterineyes

Welcome dear..

131. ashna

okay now .. next question ?

132. waterineyes

I am gone.. New post please..

133. waterineyes

Medal for solving c and e part. Ha haha..

134. ashna

:P .. i have to really give you , for spending so much time with me :)

135. ashna

you are a good human and a good teacher ;)

136. waterineyes

Really? Well, I am not..

137. ashna

what if i say you are one .. ?

138. waterineyes

Then I simply: $$\color{green}{\text{Refuse}}$$

139. ashna

and why ?

140. waterineyes

I said I am not that is why.

141. ashna

well then .. never mind , i'll have it that way :P

142. waterineyes

Never will I..

143. ashna

it is just because you are down to earth you are saying like that !