Friday
April 18, 2014

Search: Chemistry-help needed

Number of results: 109,759

English
1. 2 more commas needed; check spelling 2. 2 commas needed; delete "practice" 3. comma needed; use the phrasing in parentheses 4. comma needed; omit "the" 5. revise the first clause to match #3; comma needed. 6. comma and 2 semicolons needed
Tuesday, January 31, 2012 at 4:56pm by Writeacher

chemistry 2
You are instructed to create 800. mL of a 0.69 M phosphate buffer with a pH of 7.6. You have phosphoric acid and the sodium salts NaH2PO4, Na2HPO4, and Na3PO4 available. what is the molarity needed for the acid component of the buffer?What is the molarity needed for the base ...
Tuesday, March 4, 2014 at 3:36pm by Danielle

chemistry
what is the number of grams needed to prepare a 1.23 M solution of nitric acid if 250.0 mL are needed?
Thursday, May 19, 2011 at 2:23pm by Anonymous

Chemistry
Thank you Dr. The former is needed to find the volume of H2 in this case. I expect that once I perform the lab, the latter will be needed. You've helped me a great deal. You may expect to see me more often. I'm in your care for this semester, amongst any other Chemistry tutors.
Saturday, October 22, 2011 at 8:42pm by Martin

Chemistry help needed
How many milligram of lysozyme (MW=14,600 g/mol) are needed to make 3 liters of a 10^-6 M solution?
Sunday, September 15, 2013 at 6:00pm by Kris

chemistry
a student needed 1000 ml of a 0.10 buffer of ph 4.0. calculate the amount of sodium acetate and acidic acid needed for this solution
Tuesday, April 20, 2010 at 8:30pm by bay

Foreign languages
1. ... his behaviour. 2. comma needed 3. two commas needed 4. comma needed 5. spelling (2 errors) and comma needed 6. Don't use "pass" in this context. 7. OK
Tuesday, May 22, 2012 at 10:42am by Writeacher

Honors Chemistry
Yes, the answer you gave me for the first one was exactly what I needed -- sorry I didn't make it clear enough as to what I needed :( lol. I totally understand both explanations! Thanks!! :D
Tuesday, September 22, 2009 at 8:09pm by Emily

Chemistry-help needed
Help needed.
Saturday, October 23, 2010 at 3:15pm by MathMate

math
Draw a venn diagram to illustrate the following. In a shop 50 cars were inspected and it found that 23 needed new brakes and 34 needed new tires. 3 needed no services at all how many needed new brakes and new tires? How many only needed brakes? Please help
Friday, December 9, 2011 at 11:38am by kia

English
1. ... corruption, ... I don't understand this: "he survived a change of monarch" -- let me know what you mean here, and I'll help you word it differently. 2. ... Whig, ... wealth, ... 3. two commas needed 4. OK 5. two commas needed 6. No hyphen needed; one comma needed.
Saturday, February 18, 2012 at 2:57pm by Writeacher

Chemistry
Record the amount of heat needed to change phases for water-ice to steam using graphical analysis. Is there a one accurate amount of heat needed to change phases, I thought it varied depending the problem... Would the question be asking for the heat needed in my graph that I ...
Thursday, June 10, 2010 at 10:29pm by Amy~

Chemistry
14-pH=pOH=14-10.5=3.5 pOH=-log[OH-]=3.5 10^-(pOH)=10^-(3.5)=OH concentration in M 4.40L*(OH concentration in M)= moles of OH moles of OH*(39.997 g/mol)= mass of NaOH needed mass of NaOH needed Since 15% is 0.15g of NaOH/g of solution, solving for g of solution mass of NaOH ...
Sunday, March 17, 2013 at 1:58pm by Devron

AP Chemistry
E = hc/wavelength, solve for E in joules. 1 watt = 1 J/s, make the conversion to 5 mW, then see how many joules is needed to run 120 sec. I would then use a proportion to determine how many of the photons are needed.
Wednesday, November 17, 2010 at 5:31pm by DrBob222

Chemistry
Balance the equation first. Then, change the 22.4 g O2 to moles. Look at the coefficents in the balanced equation. That tells you how much mass of mercury(II)oxide is needed. I will be happy to critique your work, if needed.
Friday, September 21, 2007 at 1:27pm by bobpursley

English
1. comma needed 2. comma needed -- novel's title is indicated how? 3. "confined to a cottage" (not "in") 4. Is that the title of a book or an article or what? No capital on "unity" comma needed 5. OK 6. OK 7. was comma needed
Monday, December 12, 2011 at 1:51pm by Writeacher

Chemistry please help!
Please help. I have no idea how to do these 4 homework problems. 1- How many milliliters of 0.140 M HCl are needed to completely neutralize 42.0mL of 0.106 M Ba(OH)2 solution? 2-How many milliliters of 0.123 M H2SO4 are needed to neutralize 0.250 g of NaOH ? 3-If 55.2 mL of ...
Monday, February 22, 2010 at 1:30pm by Robert

Chemistry
If 62.7 ml of .208M HCL is needed to needed to neutralize a solution of Ca(OH)2, how many grams of Ca(OH)2 must be in the solution?
Sunday, February 26, 2012 at 10:08pm by Arianna

Chemistry
Why is the temperature needed to freeze ocean water lower than the temperature needed to freeze the surface of a freshwater lake?
Thursday, October 18, 2012 at 6:29pm by Anonymous

English
1. two commas needed 2. OK 3. comma needed 4. OK 5. comma needed 6. comma needed Everything else is OK.
Tuesday, September 27, 2011 at 12:15pm by Writeacher

chemistry
Oh that's true, so you're saying to measure out the amount of methanol needed for a 0.2% solution and the amount of isopropanol needed for a 0.2% solution, adding both to the same 1 mL of water, correct?
Sunday, February 2, 2014 at 9:28pm by making solutions

chemistry
suppose i want to find out how many mL of 1.0M AgNO3 are needed to provide 169.9g of pure AgNO3. what is step one in solving this problem? How many mL of solution are needed?
Wednesday, November 18, 2009 at 12:04pm by lynda smith

Chemistry help!!
mass needed: 500ml*.08, and assuming the 8 percent is the same density as water, then that is 40 grams acetic acid. volume needed=massneeded/density=40/1.049 ml
Sunday, April 22, 2012 at 12:42pm by bobpursley

Chemistry
If 1500. of hard water contains 0.019 and 0.0070 , how many moles of are needed to replace these ions? If the sodium is added to the water softener in the form of NaCl , how many grams of sodium chloride are needed?
Tuesday, September 27, 2011 at 3:11pm by Sarah

English
1. commas needed "their" = ?? 2. Pride and Prejudice (no -s) comma needed 3. spelling ~~> "people" 4. comma needed ... from her elder sister...
Monday, December 19, 2011 at 1:46pm by Writeacher

Algebra- word problem
Jordan has a photograph on his wall that is 3 in. long and 6 in. wide. He takes it to be framed which increases the length and width by 2 in. each. How does getting the picture framed change the amount of wall space needed? My choice is B- Correct?? Choices A. the wall needed ...
Sunday, May 15, 2011 at 8:14am by Mary

English
1. OK 2. comma needed 3. Please proofread and repost. 4. comma needed 5. commas needed Yes, that phrasing is fine, too.
Wednesday, September 14, 2011 at 4:36pm by Writeacher

chemistry
mols H2 needed = 0.500L/22.4L = ? at STP. mols Fe needed = 3/4 that (see the coefficients in the balanced equation.) g Fe = mols x atomic mass.
Sunday, January 13, 2013 at 8:36pm by DrBob222

Chemistry..
A chemical engineer calculated that 15.0 mol H2 was needed to react with excess N2 to prepare 10.0 mol NH3. But the actual yield is 60.0% . Write a balanced chemical equation for the reaction. Is the amount of H2 needed to make 10.0 mol NH3 more than, the same as, or less than...
Wednesday, January 2, 2013 at 8:46pm by Anonymous

English
1. Comma needed 2. OK 3. OK 4. Comma needed in 2nd sentence 5. OK 6. Huyysmans' (no extra "s" needed here)
Thursday, September 15, 2011 at 3:34pm by Writeacher

Chemistry
Suppose you wanted to find out how many milliliters of 1.0 M AgNO3 are needed to provide 169.88 g of pure AgNO3. a. What is step 1 in solving the problem? b. What is the molar mass of AgNO3? c. How many milliliters of solution are needed?
Monday, April 22, 2013 at 11:26am by Somer

English
"in the ninth century" = correct (But then you'd say, "In 9th century Rome...") 6th century (AD): 501-600 9th century (AD): 801-900 10th century: 901-1000 Remember: The first century didn't start with year 0!! It started with year 1. So the 1st century included the years 1-100...
Monday, September 5, 2011 at 9:00am by Writeacher

English
Commas needed ... again and again!! Do you still have that link? Also a comma or two NOT needed! Delete words in parentheses. There's a word needed in #6. 7 - "... his long, shiny, black hair ..."
Wednesday, November 23, 2011 at 5:18pm by Writeacher

Chemistry
Let x = mass ice. 335*x = heat needed to melt ice. 4.184*100*x = heat needed to raise T of that ice from zero C to 100 C. 2260x = heat needed to vaporize the ice at 100 to steam at 100. 335x + (4.184*100*x) + 2260x = 9574 J. Solve for x.
Friday, April 27, 2012 at 10:15pm by DrBob222

English
1. comma needed 2. comma needed 3. OK Good job! Do you see where the commas are needed?
Thursday, December 29, 2011 at 5:03pm by Writeacher

Chemistry
This is a weirdo question. The initial concn is mols PCl5 = grams/molar mass M = mols/0.500 = ? The other numbers are not needed. They would be needed if you wanted the equilibrium concn of PCl5.
Sunday, May 27, 2012 at 7:41am by DrBob222

Chemistry
What is needed for nuclear fusion to occur? pressure, a beta particle or high temperature? I think it's only high temperature and pressure needed.
Monday, July 19, 2010 at 10:02pm by Derrick

Health
1. What is needed to make blood cells? 2. What pair of workers is needed to produce estrogen? 3. What is needed to produce eleven hormones that control the actions of other endocrine glands? 4. What is needed to pass oxygen from lungs into blood vessels and welcome carbon ...
Sunday, December 4, 2011 at 9:45pm by Hayley

Chemistry
Calculate the mass of copper needed to displace 5.0g of silver from silver nitrate solution. Cu+2AgNO3->Cu(NO3)2+2Ag (Relative atomic masses:Ag=108,Cu=63.5) I got it to be 3.175g needed.
Friday, January 18, 2008 at 3:01pm by Anonymous

Chemistry help needed
This looks like a chemistry assignment.
Monday, June 2, 2008 at 4:41pm by Ms. Sue

Chemistry
Chemistry is the school subject here, not "acton high." Assistance needed.
Wednesday, September 24, 2008 at 4:22pm by Writeacher

chemistry
how do i do this \? a 4.0mg/dl standard solution is needed. To prepare 100ml of the working standard. How much stock standard of a 1mg/ml (100mg/dl) solution is needed. i dont understand this conceptually / thanks
Thursday, January 21, 2010 at 2:45am by Dan_9

Science - Chemistry
Aluminum oxide is formed from the reaction of metallic aluminum with oxygen gas. How many moles of Aluminum are needed to form 3.4 moles of Aluminum oxide? Writr the equation and balance it. 4Al + 3O2 ==> 2Al2O3 The equation tells you that 4 mols Al are needed to form 2 ...
Tuesday, January 23, 2007 at 11:14am by Sara

English
1. OK 2. use "became" -- ... it became essential to the plots and characters' thoughts and actions. 3. two commas needed 4. comma needed 5. ...which is going to be extinguished... 6. comma needed
Tuesday, November 8, 2011 at 4:13pm by Writeacher

English
3. comma needed; space needed after period 4. comma needed; spelling of 7th word 5. "introduced" You can use the word "indicate" instead of "represent" in the last sentence.
Sunday, May 29, 2011 at 3:44am by Writeacher

Chemistry
a. 100 kg H2O from 22 to 100 will require how much energy? That is mass H2O (in grams) x specific heat H2O (J/g*C) x (100-22) = ?J oil needed(lbs) = 1 lb x (?J/2.4E7) Convert lbs oil to kg. b. Same concept but heat needed is 100,000 g H2O x delta Hvap = heat needed.
Monday, February 6, 2012 at 3:49pm by DrBob222

English
1. ... in a shabby theater ... OR ... in a dingy theater ... 3. has 4. commas needed 5. comma needed 6. check verb form (plural?) comma needed
Sunday, October 2, 2011 at 4:52pm by Writeacher

English
1. ... that, on that occasion, he didn't want to do her any harm, but he did want to be kind to her. 2. comma needed 3. two commas needed 4. ... for having spoken her mind ... 5. two commas needed
Monday, February 20, 2012 at 4:13am by Writeacher

chem
In most cases, especially in organic chemistry, writing a reagent or a set of conditions (temperature, pressure, uv light, that kind of thing) above the arrow means some of that is required but no specific amount is needed. For H2SO4 it probably means that some of it is needed...
Monday, August 17, 2009 at 2:59pm by DrBob222

English
1) end punctuation needed 2) OK 3) OK 4) two commas needed 5) two commas needed; one comma needs to be removed
Sunday, September 18, 2011 at 7:09pm by Writeacher

Chemistry
My questions keep getting cut off. What am I doing wrong? Here is my question again. Thanks for the help. What is the empirical formula for a compound whose molecular formula is C2Cl6? a) CCl3 b) CCl4 c) C2Cl6 d)CCl e) more info needed I think the answer is E more information ...
Sunday, October 25, 2009 at 6:14am by Mattt K

Chemistry
How many grams of a stock solution that is 87.0 percent H2SO4 by mass would be needed to make 200 grams of a 35.5 percent by mass solution? Show all of the work needed to solve this problem.
Monday, September 2, 2013 at 5:39pm by Stephanie

chemistry
A student needed to make 200 ml of 0.1 M naOH. If the stock soluton was 0.75 M, how much of the stock solution and how much wter would be needed to make this solution?
Wednesday, May 4, 2011 at 10:33pm by Amy

Chemistry Help Please!!
We did an experiment and I don't really know how to calculate this question. If you could show me how to do one, then I could do the rest. INFORMATION: HCl = 0.1404 M We placed 0.5 g Ca(OH)2 in 100 mL of the following solutions: Flask A: Distilled Water (8.5 mL of HCl needed ...
Monday, March 26, 2012 at 7:53pm by Ally

Chemistry HELPP!!!!!!
We did an experiment and I don't really know how to calculate this question. If you could show me how to do one, then I could do the rest. INFORMATION: HCl = 0.1404 M We placed 0.5 g Ca(OH)2 in 100 mL of the following solutions: Flask A: Distilled Water (8.5 mL of HCl needed ...
Monday, March 26, 2012 at 8:47pm by Myles

English
1. comma needed 2. comma needed 3. comma needed 4. playing archery 5. OK 6. "...because it was right on the beach." 7. OK
Thursday, April 21, 2011 at 9:02am by Writeacher

Art
1. OK 2. comma needed 3. comma needed 4. comma needed -- use "tries" not past tense 5. OK 6. OK
Sunday, May 20, 2012 at 5:09am by Writeacher

Chemistry
WOULD THE VOLUME OF A 0.10M NAOH SOLUTION NEEDED TO TITRATE25.0ML OF A 0.10M HNO2 ( A WEAK ACID)SOLUTION BE DIFFERENT FROMTHAT NEEDED TO TITRATE 25.0ML OF A 0.10M HCL (A STRONGACID)SOLUTION?
Wednesday, June 12, 2013 at 8:01pm by Naomie

Chemistry
1 N204(l) + 2 N2H4(l) --> 3 N2(g) + 4 H2O(g) If you start with: 5.0 x 10^4 g hydrazine (N2H4) "in the tank": 1) How many moles of nitrogen can be created (assuming 100% yield)? 2) How many moles of water can be produced? 2) What mass of dinitrogen tetroxide (N2O4) is needed...
Tuesday, November 23, 2010 at 7:07pm by Lauren K.

Grade 11 Chemistry!
10% (m/m) sodium hydroxide solution, NaOH, is used to break down wood fibre to make paper. a) What mass of solute is needed to make 250mL of 10% (m/m) solution? b) What mass of solvent is needed? c) What is the molare concentration?
Wednesday, December 10, 2008 at 9:39pm by Kairi

Art
1. Clarify the pronouns (they, them -- make sure their antecedents are clear). 2. ... about reality ... isn't reality. 3. comma needed in the first sentence 4. comma needed after second "more" 5. comma needed
Saturday, May 26, 2012 at 5:44pm by Writeacher

Chemistry Solubility help!!!!!!!!!
INFORMATION: [HCl] = 0.1388 M We placed 0.5 g Ca(OH)2 in 100 mL of the following solutions: Flask A: Distilled Water (7.4 mL of HCl needed to titrate) Flask B: 0.05 NaOH (12.1 mL of HCl needed to titrate) Flask C: 0.025 NaOH (10.8 mL of HCl needed to titrate) Flask D: 0.0125 ...
Tuesday, March 26, 2013 at 5:51pm by Sally

Algebra ll
Cleopatra was needed barge workers, and when the word went out 175 workers showed up, that is 21/2 times the amount needed. How many workers were originally needed? (I am trying to help my niece with her homework, and we live 600 miles apart. Can you explain to me how to get ...
Wednesday, August 29, 2007 at 11:11pm by Trisha

chemistry
Another “grand challenge” for engineering is managing the nitrogen cycle. Use the nature of the chemical bond in diatomic nitrogen to explain why any management is needed for this biogeochemical cycle. With so much nitrogen available in the atmosphere, why are engineering ...
Thursday, February 3, 2011 at 7:32pm by Jazmin

Chemistry
1 N204(l) + 2 N2H4(l) --> 3 N2(g) + 4 H2O(g) If you start with: 5.0 x 10^4 hydrazine (N2H4) "in the tank": 1) How many moles of nitrogen can be created (assuming 100% yield)? 2) How many moles of water can be produced? 2) What mass of dinitrogen tetroxide (N2O4) is needed? ...
Tuesday, November 23, 2010 at 6:46pm by Lauren K.

college chemistry
Chemistry help needed.
Wednesday, October 20, 2010 at 12:22am by drwls

chemistry math
ln(M/Mo) = -kt ln = natural log M = mass left (not needed) Mo = original mass (not needed) (M/Mo) = 0.809 k = 0.693/T(half) T(half) = 5.73X10^3 years.
Wednesday, October 15, 2008 at 8:19pm by GK

chemistry math
ln(M/Mo) = -kt ln = natural log M = mass left (not needed) Mo = original mass (not needed) (M/Mo) = 0.809 k = 0.693/T(half) T(half) = 5.73X10^3 years.
Wednesday, October 15, 2008 at 8:19pm by GK

chemistry math
ln(M/Mo) = -kt ln = natural log M = mass left (not needed) Mo = original mass (not needed) (M/Mo) = 0.809 k = 0.693/T(half) T(half) = 5.73X10^3 years.
Wednesday, October 15, 2008 at 8:19pm by GK

CHEMISTRY
How much heat is needed to melt 150g of ice? and How much heat is needed to change 150g of ice into steam at 110 degrees? My heat of fusion is 361 and my percent error is 8 if you need that. Answers quickly please :(
Tuesday, March 8, 2011 at 8:00am by TaShe

Chemistry
10% (m/m) Sodium Hydroxide solution, NaOH(aq) is used to break down wood fibre to make paper. A) What mass of the solute is needed to make 250mL of 10% (m/m) solution? B) What mass of solvent is needed? C) What is the molar concentration of the solution?
Monday, May 2, 2011 at 9:28am by Saman

English
1. comma needed 2. comma needed; variations are fine. 3. delete (earned); "took turns driving," [<~~include the comma]; "stopped" is fine 4. comma needed; "I helped my father at his job."
Monday, September 12, 2011 at 8:36am by Writeacher

English
1. comma needed; ignore stuff in parentheses, yes. 2. use "went," yes; either phrasing re lunch is possible, yes. 3. use "went" rather than "moved" or "transferred" 4. 2 commas needed; keep "the" 5. comma needed
Thursday, June 2, 2011 at 1:42pm by Writeacher

Chemistry
If delta Hrxn is +, the reaction is endothermic. Look at the problem. 464.8 kJ of heat is needed to react with (how much) CaO. That is 56 g. So the heat needed to convert 10.0 g must be 464.8 kJ x 10.0/56 = ??
Wednesday, December 8, 2010 at 5:13pm by DrBob222

English
1. comma needed; wandering (not "wondering"); and (not "ad); "They are presented not statically as in a painting, but alive with motion." 2. OK 3. comma needed; portrayed (not "presented"); stretch (not strech) "in a never-ending line" 4. OK 5. comma needed; yes, what you have...
Monday, May 30, 2011 at 5:45pm by Writeacher

Chemistry - Solubility
INFORMATION: [HCl] = 0.1388 M We placed 0.5 g Ca(OH)2 in 100 mL of the following solutions: Flask A: Distilled Water (7.4 mL of HCl needed to titrate) Flask B: 0.05 M NaOH (7.5 mL of HCl needed to titrate) Flask C: 0.025 M NaOH (10.8 mL of HCl needed to titrate) Flask D: 0....
Monday, March 31, 2014 at 10:38pm by PleaseHelpThankYou!

Chemistry
2NaOH + H2SO4 ==> Na2SO4 + 2H2O How many mols H2SO4 do you have? That's mols H2SO4 = M x L = 1M x 0.050L = ? From the equation you know that 2 mols NaOH are needed for 1 mol H2SO4; therefore, 2*0.050 = mols NaOH needed.
Monday, June 11, 2012 at 1:43pm by DrBob222

chemistry
The Fe(ox)33– complex ion creates an emerald green solution when dissolved. The observed solution color of the complex indicates the size of o is: A. large. B. small. C. in between. D. inconclusive, more information is needed. The observed solution color of the complex ...
Wednesday, June 30, 2010 at 4:22am by Jin

chemistry
he Fe(ox)33– complex ion creates an emerald green solution when dissolved. The observed solution color of the complex indicates the size of o is: A. large. B. small. C. in between. D. inconclusive, more information is needed. The observed solution color of the complex ...
Wednesday, June 30, 2010 at 10:58am by ....

Chemistry
I believe I worked that problem yesterday. Perhaps not for you. heat needed to move T of ice from -10 to 0 q1 = mass x specific heat ice x delta T heat needed to melt the ice. q2 = mass x heat of fusion. heat needed to move T from 0 to 25. q3 = mass x specific heat water x ...
Thursday, January 17, 2008 at 11:03pm by DrBob222

Chemistry
Can someone please check my work? Calculate the mass of (NH4)2S2O8 needed to prepare 250mL of a 0.100M solution. I got 5.705 g. Calculate the volume of 2.00M KI needed to prepare 250mL of a 0.200M solution. I got 0.025L or 25mL. Calculate the volume of 0.100M Na2S2O3 needed to...
Saturday, January 22, 2011 at 1:55pm by Rachel

chemistry
I am going to assume that the solubility of KNO3 stated is the maximum solubility and is in water. You need to know the molecular mass of KNO3, lets say it is M. 200 cm3 is 1/5 of a litre so the number of moles needed is 8.9 mol x 1/5 = 1.79 mol the mass needed is then 1.79 x M
Wednesday, August 24, 2011 at 9:33am by Dr Russ

English
1. OK 2. 2 commas needed. 3. comma needed 4. OK 5. comma needed
Wednesday, January 25, 2012 at 3:52pm by Writeacher

Chemistry
Balanced Chemical Equation: 1 N204(l) + 2 N2H4(l) --> 3 N2(g) + 4 H20(g) If you start with: 5.0 x 10^4g hydrazine (N2H4) "in the tank": 1) How many moles of nitrogen can be created (assuming 100% yielded)? 2) How many moles of water can be produced? 3) What mass of ...
Friday, November 19, 2010 at 6:22pm by Roger

Chemistry
Balanced Chemical Equation: 1 N204(l) + 2 N2H4(l) --> 3 N2(g) + 4 H20(g) If you start with: 5.0 x 10^4g hydrazine (N2H4) "in the tank": 1) How many moles of nitrogen can be created (assuming 100% yielded)? 2) How many moles of water can be produced? 3) What mass of ...
Friday, November 19, 2010 at 6:56pm by Roger

math
5*2.5=12.5 cups needed for cakes 3*1.25=3.75 cups needed for pies 4*.75=3 cups needed for cookies 3+3.75+12.5= 19.25 cups needed in total
Saturday, February 26, 2011 at 3:09pm by Ryan

Chemistry
Calculate the volume of 2.45 M NaI that would be needed to precipitate all of the Hg+2 ion from 185 mL of a 2.44 M Hg(NO3)2. AND Calculate the molarity of an acetic acid solution if 47.81 mL of the solution is needed to neutralize 147 mL of 1.32 M sodium hydroxide.
Monday, May 6, 2013 at 3:52pm by Marsha

Chemistry - Solubility
INFORMATION: [HCl] = 0.1388 M We placed 0.5 g Ca(OH)2 in 100 mL of the following solutions: A 25 ml aliquot was used Flask A: Distilled Water (7.4 mL of HCl needed to titrate) Flask B: 0.05 M NaOH (7.5 mL of HCl needed to titrate) Flask C: 0.025 M NaOH (10.8 mL of HCl needed ...
Monday, March 31, 2014 at 10:45pm by PleaseHelpThankYou!

Chemistry
This all has to do with the definition of molarity. M = moles/L. It's that simple. moles need for 420 mL solution of 5.0 M? M x L = moles needed. moles = grams/molar mass. Substitute moles needed and molar mass, solve for grams.
Wednesday, March 10, 2010 at 3:09pm by DrBob222

chemistry
ASSUMING that ^\circ \rm C to be degrees C, then, E of one photon = hc/wavelength with wavelength in m. Energy needed to heat the water is mass H2O x specific heat H2O x (Tfinal-Tinitial). Set up a ratio and proportion to calculate the number of photons needed. Post your work ...
Monday, November 8, 2010 at 9:37pm by DrBob222

chemistry
1998 scientists using a special type of electron microscope were able to measure the force needed to break a single chemical bond. If 2.0 x 10^-9 N was needed to break a C-Si bond, estimate the bond enthalpy in kJ/mol. Assume that the bond had to be stretched by a distance of ...
Monday, September 26, 2011 at 1:04pm by Amber

chemistry help needed
Thank you.
Sunday, July 22, 2012 at 11:20pm by MathMate

Chemistry
How many grams of sucrose are needed to make 875 mL of a 39.0% (w/v) sucrose solution?
Sunday, January 27, 2013 at 4:22pm by Chemistry

Chemistry
This is a limiting reagent problem I know that because amounts for BOTH reactants are given. I do these the long way but I think that is easier. Write and balance the equation. Convert 0.l00 mol Na2CO3 to NiCO3(the ppt) assuming you have all of the NiCl2 needed. Then convert 0...
Monday, February 25, 2013 at 12:44pm by DrBob222

AP Chemistry
This is an Advance placement chemistry class. We were told to fine the materials needed to do this lab, and the procedure. i need this info so i can physically do the lab.
Tuesday, March 22, 2011 at 9:48pm by meghan

Finance
If a corporation wanted to guarantee its long term costs of financing an investment project, it could: a.) sell t-bill futures for when the funds were needed b.) buy t-bill futures for when the funds were needed c.) sell t-bond futures for when the funds were needed d.) buy t-...
Wednesday, April 28, 2010 at 10:54am by Sam

CHEMISTRY
4. The human eye is a complex sensing device for visible light. The optic nerve needs a minimum of 2.0 x 10-17 J of energy to trigger a series of impulses that eventually reach the brain. (a) How many photons of red light (700.0 nm) are needed? (b) How many photons of blue ...
Sunday, February 9, 2014 at 10:05pm by Sutheshan

English
1. comma needed 5. commas needed Everything else is fine.
Sunday, May 15, 2011 at 7:00pm by Writeacher

English
2. commas needed 3. comma needed 4. read aloud
Monday, April 9, 2012 at 7:11pm by Writeacher

Organic Chemistry
I am suppose to calculate the theoretical amount (volume) of 3M sodium hydroxide needed to convert 1.5 g of benzoic acid to its salt. Also calculate the volume of 12M HCl needed to convert the sodium benzoate back to benzoic acid. how do I go about doing this? Thanks
Tuesday, May 18, 2010 at 1:25pm by Jake

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