## ashna 3 years ago In 3 moles of ethane calculate the following. (a) no of moles of C atom. (b) no of moles of H atom. (c) no. of molecules of ethane.

1. ashna

@waterineyes

2. hanah

Answer (i) 1 mole of C2H6 contains 2 moles of carbon atoms. Number of moles of carbon atoms in 3 moles of C2H6 = 2 × 3 = 6 (ii) 1 mole of C2H6 contains 6 moles of hydrogen atoms. Number of moles of carbon atoms in 3 moles of C2H6 = 3 × 6 = 18 (iii) 1 mole of C2H6 contains 6.023 × 10^23 molecules of ethane. Number of molecules in 3 moles of C2H6 = 3 × 6.023 × 10^23 = 18.069 × 10^23

3. ashna

what about atoms ?

4. ashna

have you copy pasted it @hanah ?

5. hanah

u have to find mole not atom

6. ashna

i know that .. i want for atoms too !

7. hanah

ok

8. ashna

can you explain this ?

9. ashna
10. ashna

i had already checked the link .. only then did i come to open study

11. ashna

i didn't understand that .. so can you explain ?

12. hanah

its just as simple just multiply 3 as given in your question with the number of mole present in the formula of ethane

13. waterineyes

She is right.. But it seems you are not satisfied or you did not get that ?? Right??

14. ashna

yeah !

15. waterineyes

See I give you another example so that you get some understanding: See; Let suppose we have Water (already you have too) \(H_2O\) Now tell me how many H and O are there ??

16. ashna

does that mean whenever the qn is find the moles i should multiply the given atoms with the number of moles present ? EVERY TIME ?

17. waterineyes

Wait go slow... I explain you everything.. Just tell me what I asked..

18. ashna

2 H and 1 O

19. waterineyes

If you look Atom wise: Then there are two atoms of H and one atom of O Right ??

20. ashna

yeah !

21. waterineyes

So: For two H. there are 2 mole of H atom For one H there are 1 mole of H atom This is according to the atoms present in \(H_2O\).. Getting ??

22. ashna

yes

23. waterineyes

*is

24. waterineyes

Okay now moving forward: This is for single \(H_2O\) What if I said : for \(2 H_2O\)

25. ashna

4 H and 2 O ?

26. waterineyes

Yes.. So 4 moles of H and 2 moles of O..

27. ashna

yeah !

28. waterineyes

Similarly in your question: you can just understand your question as : \(3(C_2H_4)\) How many C and H are there ??

29. waterineyes

H_6...

30. ashna

6 C and 12 H

31. waterineyes

Sorry for \(C_2H_6\)..

32. ashna

okay 18 H

33. waterineyes

How ??

34. waterineyes

Yes now you are right.

35. ashna

is it just C2H6 OR 3(C2H6)

36. waterineyes

Ethane is just : \(C_2H_6\)

37. waterineyes

But you are given 3 moles of it : 3 Moles of \(C_2H_6\)

38. waterineyes

So you can write it as : \(C_2H_6 + C_2H_6 + C_2H_6 = 3 C_2H_6\)

39. ashna

oh okay .. understood .. so any qn like this ..i shud follow the same steps right ?

40. ashna

@hanah and @waterineyes thanks :)

41. waterineyes

Yes.. For calculating atoms in the molecule we follow the same steps..

42. ashna

okay !

43. waterineyes

Understood ?? c part you can do or not ??

44. ashna

yes that i know :)

45. ashna

can you see that in nana3456 you are still typing something ?

46. ashna

or is it just my comp wch makes me see like that ?

47. waterineyes

I am wondering by seeing that..

48. waterineyes

See this site stopped working for me when I was typing that reply.. Ha ha ha.

49. ashna

:P .. from the morning you are typing something and i were wondering why you wern't entering it :P

50. waterineyes

At that time I was replying to Nana and this site did not work properly for me then.. Sorry I could not reply to you..

51. ashna

its okay :)