## toxicsugar22 2 years ago For the following reaction, 6.73 grams of hydrochloric acid are mixed with excess barium hydroxide. The reaction yields 15.5 grams of barium chloride. 2 HCl (aq) + Ba(OH)2 (aq) = BaCl2 (aq) + 2 H2O (l) (1) What is the theoretical yield of barium chloride ? grams (2) What is the percent yield for this reaction ? %

1. electrokid

step 1. 2 moles HCL -----> 1 mole BeCl2 step 2. find gram molecular wts of HCl and BeCl2

2. electrokid

3. toxicsugar22

thsi is my first time doing this so please bear with me

4. toxicsugar22

im just practicing

5. electrokid

no problem.. try it. it is fairly easy,...

6. electrokid

7. electrokid

gram mol weight (gmw) = sum of atmic weights of all the elemnts in the molecule so, gmw of HCl = at. wt. of H + atomic wt. of CL

8. electrokid

at. wt. of Cl = ? you have to refer to your Preiodic table

9. electrokid

17 is the "atomic number" of Cl and 35.5 is the atomic wt.

10. toxicsugar22

1+35

11. electrokid

good, so, gmw of HCl = 36.5 what this means is that 1mole of HCl weighs 36.5g (g=grams)

12. electrokid

similarly, for BeCl2... notice that there are two atoms of chlorine

13. electrokid

sorry it is BaCl2

14. electrokid

practice to write it clearly.. gmw of BaCl2 = ___ + ___ + ____ = ____g

15. toxicsugar22

sorry I got 137 is the atomic number for Ba and 35 for Cl

16. electrokid

no.. atomic number = number of protons in the nucleus of an atom atomic mass number = total number of protons + neutrons in the nucleus of an atom

17. electrokid

ok so gmw of BaCl2 = ?

18. toxicsugar22

I added the two 137+ 35

19. electrokid

good now back to step 2... summarize our values

20. electrokid

@toxicsugar22

21. electrokid

you see.. those are just numbers.. I cannot help you unless you put meaning to them. gram mol wt of HCL = gram mol wt of BaCl2 =

22. toxicsugar22

1mole of HCl weighs 36.5g 1 mole of BaCI2 WEIGHS 172

23. electrokid

good.

24. electrokid

now, using step 1, 2 moles of HCl ----------- yield ----------> 1mole BaCl2 i.e, 2* gmw of HCL ------------ yields -----------> 1*gmw of BaCl2

25. electrokid

follow?

26. electrokid

27. electrokid

2*_ = __ g of HCl ---- > ____g BaCl2

28. electrokid

perfecto..

29. toxicsugar22

02*36.5 = 73 g of HCl ---- > 172g BaCl2

30. electrokid

so, 73g HCl ------> 172g BaCl2 (Theoretical) so, 6.73g HCl -------- should yield how much? (we have 6.73g HCl and Expected BaCl2 is?)

31. electrokid

no.. HCl is our "reactant"..... BaCl2 is our product

32. electrokid

no

33. electrokid

ok, so, 73g HCl ----------- reacts to give us (yield) --------> 173g of BaCl2 how much HCl do we have in our reaction? (this part from the given question)

34. toxicsugar22

15.5 is the actual yield

35. electrokid

just stay to the point... do not go jumping places.

36. toxicsugar22

6.73 is how much HCI WE HAVE

37. electrokid

good.

38. electrokid

so, if 73g HCl -------- provides -------> 173g BaCl2 then 6.73g HCl --------- should provide -----> ____g of BaCl2 this is a simple ratio..

39. electrokid

follow?

40. electrokid

STEPS!!!

41. electrokid

..... ${6.73 \times 173 \over 73}=?$

42. toxicsugar22

15.94

43. electrokid

ok. but do you understand this?

44. toxicsugar22

OK NOW i DO

45. toxicsugar22

I had to rethimk the problem

46. electrokid

good. then THIS is your theoretical yield i.e., in theory, that 6.73g of HCl should give us with 15.94g of BaCl2

47. electrokid

got it?

48. toxicsugar22

good thank you for tutoring me

49. electrokid

not done yet that is just part (a)

50. toxicsugar22

part B. is where we do actual yield times theroicatl yield / 100

51. toxicsugar22

is that right

52. electrokid

(b) % yield = (actual yield) * 100 / (theoretical yield) this value must be less than 100 actual yield = given in problem theoretical yield = calculated above

53. toxicsugar22

ok

54. toxicsugar22

so 15.5 times 100/ 15.94 =97.23

55. electrokid

yes

56. toxicsugar22

ok good

57. toxicsugar22

can you go over one more problem with me

58. toxicsugar22

you are good tutor for me

59. toxicsugar22

just so I get this done evenfurthur

60. electrokid

call it a day for today. some other time. keep practicing, put meanings to numbers and write clearly so you see what you are doing

61. toxicsugar22

ok thank you for helping me

62. electrokid

@toxicsugar22 wtf not even a medal for the pain

63. toxicsugar22

soory I forgot