Xander Posted May 5, 2011 Share Posted May 5, 2011 So I find myself struggling with a chemistry lab, and I can't afford to turn it in late again. Now my question is: can some kind soul please help me finish a chemistry lab if I private message them the instructions, the data I collected, and the questions? Quote Link to comment Share on other sites More sharing options...
Excellen Browning Posted May 5, 2011 Share Posted May 5, 2011 Here's the lab first FINDING A SOLUBILITY PRODUCT Problem: What is the solubility product constant of lime water (calcium hydroxide)? Materials: evaporating dish 0.1 M HCl saturated solution of calcium hydroxide plastic transfer pipets phenolphthalein solution stirring rod Procedure: 1. Fill a pipet with the saturated calcium hydroxide solution. 2. Add 50 drops of the solution to a clean dry evaporating dish. Hold the pipet at the same angle for consistent drop size. 3. Add two drops of phenolphthalein to the solution in the evaporating dish. (Phenolphthalein turns pink in basic solutions) 4. Fill a pipet with 0.1 M HCl. CAUTION: Be careful when handling acids. 5. Add the acid to the evaporating dish, stirring continuously. Count the number of drops it takes for the pink color to disappear. Record the number of drops needed in the data table. 6. Rinse out the evaporating dish and repeat steps 2-5 for a total of three trials. Data collected Drops of HCl used: Trial 1 - 20 Trial 2 - 21 Trial 3 - 21 Analysis and Conclusions 1. Write the net ionic equation that represents solid calcium hyroxide dissolving in water. 2. Calculate the average number of drops of HCl used. 3. Calculate the molarity of the OH- ion by using the formula M(sub a) * V(sub a) = M(sub b) * V(sub b). Where M sub a = molarity of acid, V sub a = volume (drops) of acid, M sub b = molarity of base (OH-) and V sub b = volume (drops) of base. 4. Determine the molarity of the calcium ion. 5. What is the molarity of the saturated Ca(OH)2 solution? 6. Write the solubility equilibrium expression for the dissociation of calcium hydroxide. 7. Calculate the Ksp of calcium hydroxide. 8. The accepted value for the Ksp(at 25 degrees C) is 6.5 * 10 (to the -6 power) Some answers, though I won't explain them(I sometimes had to guess what they really wanted me to do, honestly): 1. Ca(OH)2 --H2O--> Ca2+ (aq) + 2 OH-(aq) 2. (20+21+21)/3 = 20.667 3. M(HCl) * V(HCl) = M(OH-) * V(OH-) 0.1 * 2.0667 = X * 50 X = 0.0413M 4. 0.0413/2 = 0.020667M 5. 0.020667M (Molarity of Ca(OH)2 is equal to the molarity of Ca2+ in the solution I suppose) The rest of them, ugh. I'll look over them tomorrow. I've never enjoyed equilibrium calculation and I haven't done them in years. Quote Link to comment Share on other sites More sharing options...
lolDeath Posted May 5, 2011 Share Posted May 5, 2011 http://www.youtube.com/watch?v=M6k_qJ8qaAU Quote Link to comment Share on other sites More sharing options...
Bearissoslow Posted May 5, 2011 Share Posted May 5, 2011 Dat illegitimacy. If your teacher/professor finds out, you're fucked. Quote Link to comment Share on other sites More sharing options...
Zanarkin Posted May 5, 2011 Share Posted May 5, 2011 I'd help except this is beyond me D: Quote Link to comment Share on other sites More sharing options...
Xander Posted May 5, 2011 Author Share Posted May 5, 2011 (edited) Dat illegitimacy. If your teacher/professor finds out, you're fucked. Right, they really come to Serenesforest... Edited May 5, 2011 by AMU Quote Link to comment Share on other sites More sharing options...
Erk Posted May 5, 2011 Share Posted May 5, 2011 I'd help except I'm barely pulling a B- in chemistry. Quote Link to comment Share on other sites More sharing options...
Claude C Kenny Posted May 5, 2011 Share Posted May 5, 2011 Right, they really come to Serenesforest... I think he means if they start asking you questions or for a demonstration. Quote Link to comment Share on other sites More sharing options...
Xander Posted May 5, 2011 Author Share Posted May 5, 2011 I think he means if they start asking you questions or for a demonstration. If he meant that, he didn't make it clear. Also, my teacher doesn't ask for demonstrations or questions since, well, we've already done the lab. Quote Link to comment Share on other sites More sharing options...
Kriemhild Posted May 5, 2011 Share Posted May 5, 2011 So I find myself struggling with a chemistry lab, and I can't afford to turn it in late again. Now my question is: can some kind soul please help me finish a chemistry lab if I private message them the instructions, the data I collected, and the questions? Sure, I can at least try. Quote Link to comment Share on other sites More sharing options...
BK-201 Posted May 7, 2011 Share Posted May 7, 2011 Help =/= Giving the Answer without explanation. If you give help like that they usually end up drowning, just ask the kids who purely rely on calculators. Quote Link to comment Share on other sites More sharing options...
Zanarkin Posted May 7, 2011 Share Posted May 7, 2011 (edited) just ask the kids who purely rely on calculators. ... ... This reminds me i should go practice my on multiplication/adding/substracting... lol i've been so used to my calculator i'm usually some numbers off... What a coincidence btw, today we just started learning about solubility of substances. Edited May 7, 2011 by Jhen Mohran Quote Link to comment Share on other sites More sharing options...
Bearissoslow Posted May 8, 2011 Share Posted May 8, 2011 Right, they really come to Serenesforest... No, more like if they google your hypothesis, data, abstract, etc. Quote Link to comment Share on other sites More sharing options...
BK-201 Posted May 8, 2011 Share Posted May 8, 2011 I expect him to be more pleading if he wants help. Quote Link to comment Share on other sites More sharing options...
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