# drbob222

Most popular questions and responses by drbob222
1. ## Chemistry!

When 2.5g of NaOH were dissolved in 49.0g water in a calorimeter at 24.0 C, the temperature of the solution went up to 37.1 C. a. Is the solution reaction exothermic? Why? The temperature or the water went from 24.0 to 37.1 which is an increase. If the

2. ## Chemistry

delta T = ikfm delta T is the amount f.p. is lowered. i is the number of particles; i.e., Na3PO4 will have i = 4 (3 for Na and 1 for PO4). m is molality. k is a constant and need not enter into the calculations. Arrange the following solutions in order of

3. ## To Morgan

Where are you getting all of this stuff? What university/college? Where do the exercises(questions) come from? What sources to you have for study? What percentage are you getting from Jiskha? Thanks. I'm just curious.

As an interested bystander, let me add just one bit to the replies and counter responses. It IS NOT correct Internet behaviour to post full name, address, etc etc. Predators are everywhere. Student's should not use their real name (first name is OK) but

5. ## To Sheryl: polarity

The exact question is: Benzyl alcohol (bp 205 degree C) was selected by a student to crystallize fluorenol (mp 153-154 degrees C) because the solubility characteristics of this solvent are appropriate. However, this solvent is not a good choice. Explain.

6. ## chem

Kw = KaKb. With this equation you can convert any Ka to Kb and the reverse. Codeine (Cod), a powerful and addictive painkiller, is a weak base. a) Write a reaction to show its basic nature in water. Represent the codeine molecule with Cod. b) The Ka for

7. ## kilauea

I see in the news reports that when the lava hits the ocean there is a spray of HYDROCHLORIC ACID. I don't see any way HCl can be formed. Acid, yes. H2SO3 yes. But not HCl. Any comments? Thanks.

8. ## To Mara

I have posted an answer for your question on acetone and ethanol (equimolar solutions) to equal 1000 mL. It's back on page 3 at the time I write this. Post your work if you get stuck and I suggest you repost at the top of the board. We will find it easier

Opinions are ok but anything with identifying information will be removed. In fact, why don't you retype your question and omit the part about including name, address, et al. and we can get someone to remove your original post. ok.thanks,do you think you

10. ## chem

HCl is a strong acid and ionizes 100%. NaOH is a strong base and ionizes 100%. We have no way of knowing the pH of HCl + H2O because the problem doesn't state the amount of HCl added or the concentration of HCl. For the NaOH + HCl ==> NaCl + HOH. NaCl in

11. ## REPOST!PLZ HELP!ALGEBRA!

You give up too easily. How? I posted how to get the answer below at the original question. OK but I replied... As did I. Well...I replied...again... Maybe you do understand this for horizontal lines. If you interchange x with y, vertical and horizontal

12. ## To Derr

You have made a couple of uncalled for comments to a couple of questions. Your remarks are not only not necessary but they take away our time in reading them to know they are nonsense. This board tries to help students. You are helping; please desist with

13. ## Chemistry (Check)

Are most factors unity? Is this True or false I'm thinkin true.. The actual size of a measurement multiplied by a conversion factor remains the same, beacause the measurement being converted is multiplied by unity. okay

14. ## Chemistry Equation(again)

What I wrote is the balanced ionic equation. The ++ are written as exponents and could be written as we usually do it as Cu^+2 + Zn ==> Zn^+2 + Cu. For the molecular equation, it is Cu(NO3)2 + Zn ==> Zn(NO3)2 + Cu So the ionic equation for adding

15. ## math

distance = rate x time or d = r*t car traveling 40 mi/hr goes 40 mi/hr x 1.5 hrs head start or 60 miles head start. Let t = time bus and car travel. car travels distance of r*t = 40*t. Car already had 60 mi head start. Total distance car traveled is 60 +

16. ## Chemistry

Al2Se3 (s) + H2O (sub>(l) ==> Al(OH)3 (s) + H2Se(g) You can see that this reaction produces hydrogen selenide gas. But it will be wet because of the water. I can't draw diagrams on the computer so you will need to research your text and notes to see how to

17. ## math

I would let #1 = x. Then #2 = x+1 #3 = x+2 #4 = x+3 The problem says we want the sum of the first three. That will be x + (x + 1) + (x + 2) and that should be 60 more than the fourth. The fourth is x + 3; therefore, set them equal and add 60 to the fourth.

18. ## Chemistry

delta G reaction = delta G products - delta G reactants. Hydrogen peroxide is used as a bleachin agent, a disinfectant and medicinally as a topical antibacterial agent. Hydrogen peroxide decomposes according to the reacton 2H^2O^2(l)-->2H^2O(l)+o^2(g) A.

19. ## Math

3x-4 to y+15 is constant and y=3 when x=2 then when y=12, x equals? My answer was 13. Im not sure how to solve this question. Could you please go through the steps so I can see they match up with mines. My Steps: 3x-y:y+15 The original problem above says

20. ## Math

I have a question my brother asked me but I need a math expert. You have two interlocking circles and the radius of circle B goes through the center of circle A and of course the radius of circle A goes through the center of circle B. The radius of each

21. ## To Jessica

Sorry, but I made two errors. Monocalcium phosphate is monocalcium monohydrogen phosphate which is CaHPO4. The Ca is +2, H is +1, and PO4 is -3 so the +3 and -3 balance. And Bob Pursley did NOT suggest that name of monocalcium dihydrogen phosphate, he was

22. ## chem

frozen carbon dioxide, CO2. what is dry ice

23. ## chemistry

I don't think there is any benzene in Elmer's glue. In fact, I suspect finding something with benzene in it will be tough to do unless you have some OLD OLD bottles of something. Its a carcinogenic thing. If you are looking for something aromatic (meaning

24. ## Chemistry

Let's do 1 and 2 and go from there. I will get you started. Take a 100 g sample. That means we have 19.9% C = 19.9 g C 46.7% N = 46.7 g N 6.67% H = 6.67 g H 26.7% O = 26.7 g O Find mols of these amounts. mols C = 19.9/12 = 1.66 mols N = 46.7/14 = 3.33 mols

25. ## Chemistry

CoCl2 is a compound that is blue when it is dehydrated and pink when in its hydrated form. I have seen a solution of CoCl2 used to paint a coloring book type figure (on paper). This is hung outside and gives a blue color when the air is dry and pink color

26. ## To Kelsey

Your buffer problem has moved down quite a bit but I've responded to your last response with my own response.

27. ## science( chem)

Basically what color is yellow when they say "Yellow"? The titrations I have done are light yellow when approaching the end point but whatever color you see is what you get, I suppose. So titrate to a very light color. Would the extra 5ml of starch

28. ## Chemistry

Think about this. Then let us know what you think and why! The answer should be obvious if you think about it. A liquid in a stoppered flask is allowed to stand at constant temperature entil the liquid level in the flask remains constant. which condition

29. ## SCIENCE

(aq) means the solution is dissolved in water used as a solvent. (l) means the COMPOUND (not element, usually) is a pure liquid. (g) means gas and (s) means solid. In the equation below, HCl(aq) + NaOH(aq) -->NaCl(aq) + H2O(l)This means that an aqueous

30. ## Algebra

17.5 lbs x 20 min/lb = ??min Notice how the unit we don't want (lbs) cancel leving the unit we want (time in min). A turkey is to be cooked 20 minutes for every pound of weight. How long should the turkey be cooked if it weighs 17.5 pounds? For every

31. ## Normality headache(thx BobPursley and Dr.Bob)

And many thanks for the thanks. All of us like to think that we offer a helping hand. Both individually and as a group I think this group does that. Good luck to you with your finals and I hope we see you when your next semester/quarter starts. And many

32. ## To Devron

Since you are a biochemist please look at the post below by C. I tried answering the question but I really don't understand the question. Perhaps you can help.

33. ## TO M--urgent

I named that compound as cis and it should be trans. The I atoms are on opposite sides and that's trans, not cis.

34. ## Chemistry

As I read it, the question provides you with a word description of the production of diesel fuel, gasoline, lighter gases such as ethane and propane, as well as some of the refinery operations such as cracking. Your job is to take this word description and

35. ## Chemistry

http://www.google.com/search?hl=en&ie=UTF-8&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=trifluoroacetic+acid&spell=1 What would happen to the strength of acetic acid if the three hydrogens that were on thte adjoining carbon were replaced with fluorines? It

36. ## chemistry

I think, by convention, most would consider the solvent as the major component and the others as solutes. Actually, however, it dosesn't matter. I just read that when one liquid is dissolved in another, the minor component is usually considered the solute

37. ## Chem

Look on your calculator. You know the definition of pH. It is pH=-log(H^+). Well, we have the same thing in pKa, pKb, pOH, pKw, etc etc. pKsp = -log Ksp. Punch 57.685 into the calculator. Now change the sign to make it negative. Now look for a button that

38. ## Chemistry

Count the electrons. HCN I see 10. NCCN I see 18. What noble gas has an atomic number of 10? of 18? State the noble gas whose electron configuration is attained in the following Lewis structures. a) H:C:::N: (cyanide) b) :N:::C:C:::N: (cyanogen)

39. ## chemistry

Everything is neutral. Touch a table, a chair, a desk, a tree, and you don't get a shock. Compounds are neutral. So Al2O3 must be neutral. Al has a valence of +3. Oxygen has a valence of -2. Now, let's add the charges. 2 Al @ +3 each is +6. 3 O @ -2 each

40. ## To Jaimi--chemistry

I responded to your post(the one on ratio of +/- charges) that's way down the list (I think on page 2 or 3 by now). Here is a link. http://www.jiskha.com/display.cgi?id=1429203638

41. ## To Breanne

I responded to that chocolate milk/ice problem. Here is a link to it. http://www.jiskha.com/display.cgi?id=1357962576#1357962576.1358029768

42. ## To CC

Here is the question you initially posted @ 10:22 last night (Sunday) with my responses. Here are the corrections I made. Check my arithmetic. http://www.jiskha.com/display.cgi?id=1269310966

43. ## Chem

The atomic numbers and masses must added up on both sides of the equation just as we must have the same number of atoms on each side of an equation when it is balanced. Ejection of a "thing" with 2 protons and 2 nuetrons is a He nucleus which is an alpha

44. ## To TOM

I accidentally erased your post on the hydrolysis of various anions. The answer is Kb(for the anion) = (Kw/Ka for the Ka for the acid) where Ka will be Ka for monoprotic acids, k2 for diprotic acids, or k3 for triprotic acids So to make OH^- the smallest

45. ## To Laura/Joseph

I have taken care of the answer to the SO3 ==> SO2 + O2 equilibrium problem that we worked on last night about midnight. You should obtain the correct answer now.

46. ## To John

If you have that question about the N2O4/NO2 equilibrium I can help if you re-post. I can't find it. I think you posted it Saturday but it may have been Sunday.

48. ## To yvonne/GK

Yvonne. Did you type all of the question about osmosis? correctly? I have struggled with it and something about it doesn't seem right. GK. Doesn't the NaCl enter the equation? And shouldn't the mass MgCl2 be less than 0.5000 gram? The total NaCl + MgCl2

49. ## Chemistry

Do you know how to set up the ICE? That's what you need to do. If you know but are confused, tell us what you don't understand about it. At 55 degrees celcius, the K for the reaction: 2NO2 (g) N2O4(g) is 1.15 Calculate the concentration of N2)4(g) present

50. ## Chemistry-

Yes, both are endothermic; however, the first one is between gases and the second one APPEARS to be (it isn't balanced with charge) a dissociated of a solid. Therefore, the first one will be much more sensitive to pressure changes than the second (if it is

51. ## chem

Sorry about that. I don't know why it did that? I will try to recap the two or three sentences I read. The oxygen molecules dissolve in H2O in the spaces between the molecules of H2O. Liquid water consists of a network of hydrogen bonded water molecules.

52. ## Chemistry

You do it by finding Uuh in the periodic table and knowing that it will have chemical properties that are similar to those in the group with it. Here is a periodic table on the web. Find element #116 and observe the other elements in the same group (O, S,

53. ## Reposted - math - Ashley's question

L=length w=width ============ eqn 1 is 2L + 2w = 28 eqn 2 is w= (1/2)L+2 =========== solve for L and w. Post your work if you get stuck. http://www.jiskha.com/display.cgi?id=1169164168 Posted by Ashley on Thursday, January 18, 2007 at 6:49pm. John made a

54. ## vapor pressure

762 + vp ethanol = total pressure. Dalton's Law of partial pressures. The total pressure in a flask containing air and ethanol at 257C is 882 mm Hg. If the pressure of the air in the flask is 762 mm Hg, the vapor pressure of ethanol is ?mm Hg.

55. ## Science/chemistry

Those are the two COMMON oxidation states. What are the charges of the two ions of copper? +1 and +2. Copper(I) and copper(II). cuprous and cupric.

56. ## To sam!

Was the five part unknown question for compounds A through E yours? If so, did you get it answered ok? no it was not mine! can you please check my math? can you please check my math?

57. ## @shenaya

I posted a response to your Ksp/K but I was late doing it. Hope you saw it.

58. ## To Kibito

I posted a response to your last two queries and now I can't find your original question nor my answers. Did you get everything taken care of on that H2S problem? My final answer was x = 0.00167 but also talked about how to solve the cubic equation using a

59. ## To Tracey

Regarding the FeO==> Fe(OH)3 problem below, take a look at the additional post. Here is the link. http://www.jiskha.com/display.cgi?id=1429650539

60. ## Quicken report

Does anyone know details about quicken investment reports? My investment report suddenly won't work.

61. ## To Tammy

See the answer to the problem you posted about 10E and 11E. I unintentionally put the 10 and 11 as subscripts in my answer to your question last night instead of superscripts as above. The answer I gave you is correct but I should have used superscripts

62. ## Chemistry

-856.7 kJ/mol is delta Gfo. Same book I used for you yesterday. Pretty good freshman text, huh? I think there is a site but this was quicker. Okay, now I need the delta G for SiO2. Maybe you have a website or something. Yes, very good text. Much better

63. ## chemistry

It forms NH4Cl, ammonium chloride, which is soluble in the water.

64. ## Math

Is that 6%/year simple interest? If so, then \$500 x 0.06 = \$30 for one year. So for 90 days, \$530 can't be correct. I would like to have an account that would more than double in a year, much less in 90 days. The Investors Club invests \$500 at 6% simple

65. ## To Melinda

Look at the last response to your U-?? question. I wonder?? That is what my book said...so I really don't know.

66. ## Chemistry

This may help a little. Although this may appear to be all about temperature, read thourough it and note that temperature denatures the enzyme and how that affects the K and the Arrhenius equation. (Broken Link Removed) An enzyme gets denatured at high

67. ## science

No question was posted. Try again.

68. ## unscrambling word

Looks like parade to me. what is this word here are the letter dapear http://www.ssynth.co.uk/~gay/anagram.html That is an easy to use word solver. Paste or type in the letters, and solve! what is the spanish word

69. ## science

Go to www.webelements.com and click on neon (element # 10). You can read all about both physical and chemical properties of neon.

70. ## Weighted Averages

I am assuming this is a 1,000g mixture. 42% H3BO3 = 420g H3BO3/(420g H3BO3+580g H2O)= 0.42 by mass. 420g H3BO3/(420g H3BO3+580g H2O+Xg H2O)= 0.06 Solve for X Check my thinking. Check my work. There is an alternative approach. You want to dilute it by a

71. ## Repost for Dora

solution is made by mixing 20.0 mL of toluene C6H5CH3d=0.867gmL with 150.0 mL of benzene C6H6d=0.874gmL. Assuming that the volumes add upon mixing, what are the molarity (M) and molality (m) of the toluene For Further Reading * chemistry - DrBob222,

72. ## chemistry - s103

Post your question. Perhaps we can help. Is there anyone out there who understands Q5 of tma06 for s103? I don't understand a word of it hi i think that the functional group are NH2 and the c=0 does anybody come up with that they to me are all amine part

73. ## chemistry

Look at gold. It has an atomic number of 79. Adding 1 proton would make it have 80 protons and that element (from the periodic table) is mercury. Look up the prices of Au and Hg and compare. Frankly, I would rather have Au (a solid) than Hg, (a liquid).

74. ## DRBOB22 I REPLIED TO THE OTHER QUESTION!!

Responded to the original post and follow up at original site. If you have trouble finding it I can come back and paste the asnwer here. !

75. ## MSDS sheet

Does anyone know where I can get a free MSDS sheet WITHOUT giving my complete biography? I don't mind an email address and even a name but land mail address, phone number, number of adults in household, cars in household, fax number, and other garbage is

76. ## To Michelle

I posted a response to that potentiometric analysis problem but it's pretty far down the list. Let me know if you can't find it and I can help.

77. ## To Nina

I think you transposed the numbers for mass proton on your post yesterday which may be the reason you had trouble getting the answer in the book. I've posted a response at the original post which can be found here.

78. ## To Annabelle

I have removed your extraneous answers from the last four or five posts. Please do not respond if you don't know the answer. If you persist in responding with rubbish you will be banned from this site.

79. ## To Sophia

Posting the exact question more than once is superfluous and doesn't get an answer any faster. Miranda and another screen name did this yesterday. Perhaps you did all of them. At any rate, just post once please.

80. ## science(chem)

Breathing too much alcohol or too much HNO3 surely would not be very good but I doubt there would be a reaction that would produce toxic fumes other than the fumes from the HNO3 and/or the ethanol. On similar note, just yesterday an 18-wheeler spilled a

81. ## To Dr Russ

I hope you come around often. We need someone with a little organic background. Mine is TOO little (and too late!).

82. ## science

Try MgBr2 and I expect you can balance it. i got a balancing equation problem i gotta get this to balance Mg(OH)2+ HBr --> MgBr + H20 so far i'v gotten it down to 2Mg(OH)2+ 4HBr --> 2MgBr + 4H20 but it's still not balanced,so can someone please balance

83. ## math

x=12 so x is positive. is this equation negative or postive? 2x=3x-12

84. ## Water

One way is to collect rain. Another way is to erect cone shaped metal objects on which water will condense at night and run into a container. There probably are more esoteric systems but this should get you sarted. If you don't have any machines or modern

85. ## To ajones51

Tough pH question #2 answered on page 2 a/o midnight CDT. It will continue to move as time marches. I hope you see the post.

86. ## Chemistry

Here goes. I am NOT an organic chemist so please obtain other sources for information; i.e., don't take my work as gospel. a) I believe the second one you list is more reactive because the first one is sterically hindered due to the isopropyl group. And

87. ## To Gabby and Jean

I have done as asked and worked that Na2C2O4 + LaCl3 problem in some detail. I've posted it at the ogiginal site; here is a hot link to it. http://www.jiskha.com/display.cgi?id=1324010745

88. ## To Rachel

I'm sorry to take so long to get back. All of the C atoms are sp2 hybridized. There are no sp3 hybridized C atoms Here is a link to that post on Sunday. http://www.jiskha.com/display.cgi?id=1295798102

89. ## Naming alkanes

Its been a long time since I did this but I believe you pick the longest chain. If there are double and triple bonds involved, pick the longest chain that contains the double bond plus single bonds to go with it (but that is for alkenes isn't it?) When

90. ## science

What do you think it does to the surface tension? why does adding soap to water reduce waters cohessiveness?

91. ## Powers!

1. Should be 8a15 but I think that is just a typo because the * and 8 are on the same key of the keyboard. 2-4 look ok to me. 5. What you have looks ok to me; however, can't these two terms be multiplied to give 200x8y9 ? Yeah sorry about #1 that's what I

92. ## To Lindz

If you see this post, respond here for a follow up on previous questions about reactivity to double bonds.

1. ## Chemistry

I'm confused with the numbers. The pH of a 100 mL acetic acid solution that is 0.1 M (100 mM) is 1.4E-3 for (H^+) or pH of 2.85 and not 3.20. Does this mean the solution is not pure acetic acid? Also did you make a typo on pKa acetic acid. Is that really

posted on December 12, 2019
2. ## Chemistry

What do you think?

posted on December 11, 2019
3. ## chemistry

40.7 kJ/mol x #mols = kJ 40.7 kJ/mol x #mols = 1.50 kJ. Solve for # mols. If you want grams, convert mols to grams by grams = mols x molar mass = ?

posted on December 11, 2019
4. ## Chemistry

Metals in the activity series will displace any ION BELOW it. For example: Al metal is above Cu in the activity series; therefore, the following reaction will occur. 2Al(s) + 3Cu^Cl2(aq) ==> 3Cu(s) + 2AlCl3+(aq) But Cu metal is below H in the activity

posted on December 11, 2019
5. ## Chemistry

pKa + pKb = pKw = 14

posted on December 11, 2019