Kaelin J

Need help trying to find the Molarity of NaOH.

Here's what I know.

Mass of dry NaOH: .683g

Mass of final solution: 169.213g

Percent by mass NaOH: .404%

Mass of dry KHP: 3.141g

Mass of KHP contained in each 25.00 mL sample: .3141g

Moles of KHP contained in each 25.00 mL sample: .001538 Moles KHP

Standardization of NaOH

Final V (mL) / Initial V (mL) / V NaOH (mL) / V NaOH (L) / Molartity of NaOH

24.4 / 0.00 / 21.6 / .0216 / Need Help

27.8 / 0.00 / 22.2 / .0222 / Need Help

27.7 / 0.00 / 22.3 / .0223 / Need Help

27.6 / 0.00 / 22.4 / .0224 / Need Help

27.9 / 0.00 / 22.1 / .0221 / Need Help

The 0's in the table above represent the burets initial volume, it starts at 0 and works it's way down to 50.00ml, so since it says 0.00mL, that just means that's what it was started out, the amount we used is the V NaOH (third column). The fifth column is what I'm confused about, I can't finish the rest of my report until I figure out how I do this.

How we thought we were supposed to find the Molarity of NaOH was Moles over liter since that is the formula. We tried this by doing .683g NaOH (dry mass of NaOH) divided by 40.00g NaOH (Molar Mass) to give us the moles of NaOH we used. Then do that over the liters we used, (column 4). Example of this would be .0171Moles / .0284 L = .602 M, apparently this answer is 5 or so times larger than what we should've gotten.

Any help would be much appreciated. Sorry about the long explanation, just wanted to put you up to speed and maybe help us out for where we went wrong. THANKS!

Write down the "molecular" equation and the net ionic for HCl solution added to solid CaCO3. Include phase labels.

Somehow H2O supposedly plays a role in this equation, would love it if someone could explain that to me.

You will prepare 40.0 grams of NaCl solution that is 0.90% by mass. Calculate the mass of NaCl that is needed.

Please show work, I do not remember how to do these types of problems.

This is part 2 of my previous question, here's the link to my other question: http://answers.yahoo.com/question/index?qid=200912...

From the average concentration of the NaOH solution above, calculate the concentration of your "new" acid solution separately for each titration in Part C.

My data from the experiment:

Unknown number/letter : 7

Volume of HCl from graduated cylinder used in each titration: 10.00mL

Titration # / Final buret volume / Initial buret volume / Total volume NaOH

4 / 5.22mL / .44mL / 4.88mL

5 / 5.41mL / .35mL / 4.95mL

Thanks for the help!

Consider the following reaction at equilibrium.

2KClO3 (s) (arrows going both directions) 2KCl (s) + 3O2 (g)

Predict the effect (shift right, shift left, or no effect) of:

a) adding KCl to the reaction mixture.

b) adding KClO3 to the reaction mixture.

c) adding O2 to the reaction mixture.

d) removing O2 from the reaction mixture.

Thanks for the help, 10 points if you can give, as well as explain, the answers.

When vinegar is added to a solution of sodium bicarbonate, the mixture immediately begins to bubble furiously. As time passes, however, the bubbling becomes less and less. Explain why this is so.

10 points if you can help me out by explaining this!

I plan on taking the General Chemistry sequence, was just wondering how hard it is, could you post some example questions that you remember from like the first couple weeks, (General Chemistry I). Would you recommend it for someone who only got a B in Chemistry?

Use the concentration of the sodium hydroxide , ( 0.133 M), and show how you would find the unknown concentration of an acid solution where 10.00 mL of the acid was titrated with 11.35 mL of the base.

Calculate the pH of each of the following Solutions

c) .0109 HBr

d) 7.02 x 10^-5 M Ba(OH)2

Thanks for the help, please show your work! I need to know how to do for an exam this week, 10 points for best answer.

Four solutions of unknown NaOH concentration are titrated with solutions of HCl. The following table lists the volume of each unknown NaOH solution, the volume of HCl solution required to reach the endpoint, and the concentration of each HCl solution. Calculate the concentration (in M) of the unknown NaOH solutions in each case.

NaOH Volume l HCl Volume l HCl (M)

a) 5 mL l 9.77mL l .1599 M

b) 15 mL l 11.34 mL l .1311 M

Thanks for the help, please explain how you did it, need to know how for my exam. Of course 10 points for someone who shows best answer and how to do it.

A 2.5-L sample of a 5.8M NaCl solution is diluted to 55 L. What is the molarity of the diluted solutions?

I need some help with this one, all I know is M1V1 = M2V2, not sure what plays what so if you know how to do this, your help is much appreciated! 10 points for the answer that is correct and shows work. Thanks!

For the reaction shown, calculator how many grams of oxygen form when each of the following completley reacts.

2KClO3 (s) -- > 2KCl (s) + 3O2 (g)

a) 2.72g KCl03

b) .361g KCl03

Appreciate the help very much so! I'd be very grateful if you could show your work since this will be on my exam next Thursday. 10 Points to best work shown correctly obviously :).

Ok, so there's this new supplement called 1-Andro RX, in fact if you don't know what I'm talking about up to this point I'd prefer you not attempt to answer, (sorry but thank you for doing so). I am 18 years old and would like to test this out in a 6 week cycle using 6 oxo as my PCT. This will be my first cycle ever and I figured why not try it, they are after all 100% legal. Any suggestions on what I can do to improve this or why I shouldn't due to my age? Much appreciated for the help and 10 points for a good answer of course who knows what they are talking about.

To communicate what compounds form when they dissolve in water.

NaCl

CaCl2

HCl

Prefer if someone who knows about this stuff could help, thanks.

Need help with a chemistry problem. When an electrolyte is strong, weak, or non electrolyte, does it produce few, many, or no ions when in water?

Please READ THIS ALL.

I am having trouble getting my L1 L2 spots back on my chart. I accidentally hit delete on them thinking it would clear the tables but it actually delete the two columns instead. Now it just shows the L3 L4 L5 and L6 lists.

Does anyone know how to get my L1 and L2 lists back?

I've memorized just about all I could and I have 3 hours until my Mid-term, I just want to throw these last bit of notes on my TI-83.

I'm looking for a good way where I can just access it through a program and still be able to use my calculator for other problems.

I can make her curl her fingers but I just can't make her curl her toes.

Any tips? I've tried using my fingers but she just won't curl them, they are as straight as ever. Her fingers are easy to bend, I can do that with just my hands. Any tips on curling those darn toes? I was told that the best way to please a woman was to curl her toes but she just won't let me!

X^2 + y^2 + 4x + 2y - 20 = 0

If possible please include how you came up with the answer with step by step directions or whatever you can.

So far I have this:

Group like terms

(x^2 - 4x) + (y^2 - 2y) = 20^2 I think

Then I'm not sure if I'm supposed to complete the square or what, also not even sure if I'm starting off in the right direction, thanks for any help you can give!

My macbook battery won't light up when I plug it in, does this mean the battery is friend and I need to buy a new one or what? My warranty just ended 2 weeks ago sadly. 1 Year 2 weeks 0 problems, why oh why don't warranties last 1 year 2 weeks!?