SMARTscience Posted April 10, 2012 Share Posted April 10, 2012 Hi, I really don't understand this lab and I need help with it:( 1. Add 10 drops of 0.050mol/L hydrochloric acid to a 100 ml beaker. 2.Transfer a small amount of indicator to the acid sol'n by placing one drop of phenolphthalein sol'n on a watch glass. Touch the drop with the glass rod. 3.Place the beaker on the white sheet of paper. 4. Add the saturated sol'n of calcium hydroxide, drop by drop, to the hydrochloric acid sol'n until the sol'n turns a permanent pale pink. 5. Record the # of drops of CA(OH)2 added. 6. Conduct 3 trials so that an average can be taken. I) Determine the average # of drops of CA(OH)2 sol'n that you needed to neutralize 10 drops of 0.050 mol/L HCl (aq) II) Use the balanced chemical eqn for the neutralization of HCl (aq) with CA(OH)2 to determine the concetration of the hydroxide ion, in moles per litre. III) Use the concentration of the hydroxide ion to determine the concentration of CA(OH)2 in moles per litre. IV) Calculate KSP for CA(OH)2. My friend agreed that he would do this lab so I really don't know how to do it. But he had no idea, and I don't want to fail. So can anyone help me out? I just need to understand how to do it, and I'll do it on my own if you can give me the steps please, thanks alot in advance I'd appreciate it if the help was provided fast. Link to comment Share on other sites More sharing options...
hypervalent_iodine Posted April 10, 2012 Share Posted April 10, 2012 My first bit if help is to to advise you do your assignments earlier than the day they're due. Your GPA will thank you. I'll look at the question when I get home, but for now I'm moving this to homework. Link to comment Share on other sites More sharing options...
SMARTscience Posted April 11, 2012 Author Share Posted April 11, 2012 Thanks for the reply, I'm in highschool;) and thanks for taking your time. The problem is, I got a whole work load this semster =.= Link to comment Share on other sites More sharing options...
SMARTscience Posted April 12, 2012 Author Share Posted April 12, 2012 Could someone please help, it's been a while. Link to comment Share on other sites More sharing options...
hypervalent_iodine Posted April 12, 2012 Share Posted April 12, 2012 There's no way for you to do this accurately. "Drops" are by no means a standard unit of measure, so you'll first have to come to some conclusion as to how many mL there are per drop. After that, well, this is homework so I'm not giving you the answer. What do you think you need to do? Ask yourself what has happened when the solution has a neutral pH and what that might mean in terms of solubility. (Sorry this took a while for me to reply to.) Link to comment Share on other sites More sharing options...
SMARTscience Posted April 12, 2012 Author Share Posted April 12, 2012 Np, and um I'll try it over again O_o but this is a lab not homework:( Link to comment Share on other sites More sharing options...
SMARTscience Posted April 12, 2012 Author Share Posted April 12, 2012 Np, and um I'll try it over again O_o but this is a lab not homework:( Link to comment Share on other sites More sharing options...
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