Chemistry - October 2006

2006-10-08 08:56:18 · 10 answers · asked by Anonymous

What mass (in grams) of CaCl2(s) must be dissolved in pure water at 10.0 deg Celsius to make a 27.0 mL solution and to increase the solution temperature to 16.2 deg Celsius? Assume that there is no heat loss from the solution and that the solution has the same physical properties as pure water.
Pay particular attention to sign and significant figures.
If you wish to use scientific notation, use the "e" format - eg. 7.31e4 = 73100 & 1.90e-2 = 0.0190. Do not enter units.

Data:
DHsol(CaCl2)(s)) = - 82.8 kJ.mol-1

specific heat of water = 4.184 J.g-1.deg-1

density of water = 1.00 g.cm-3

molar mass of CaCl2 = 111 g/mol

2006-10-08 08:50:33 · 3 answers · asked by darksoul3029 1

a.) C2H5OH
b.) MgCl2
c.) NaCl
d.) NaHSO4
e.) CaSO4

2006-10-08 08:35:26 · 1 answers · asked by Anonymous

2006-10-08 08:28:10 · 1 answers · asked by Anonymous

Ok so i have to do this titration problem and its really complicated!! If you could help me on any part of this, it will be good help!

A 50 ml solution of oxalic acid (H2C2O4) requires 24.35 ml of 0.125 M NaOH to neutralize both protons. It takes 15.83 ml of KMnO4 (Product Mn^+2) to react with all the oxalic acid in another 50 ml sample of oxalic acid (product CO2). A 2.5 g sample containing Iron II chloride is dissolbed in acid and titrated with 31.87 mL of the KMnO4 solution.

a) write three balanced equations for the reactions
b) Whcih compounds are the reducing agents and which are the oxidizing agents?
c) What is the concentration of thte permanganate solution in this problem?
d) what is the percentage of iron in the solid sample?


If could get the 3 balanced reactions i could try to work it out.
the first one i got H2C2O4+2NaOH-->2H2O + Na2C2O4
the next one is KMnO4+H2C2O4--> ?? is it CO2 + Mn^(+2)?? idk
last 1 : FeCl2+ KMnO4 --> Fe(MnO4)2 + KCl
are these right?

2006-10-08 08:26:03 · 2 answers · asked by Anonymous

what is the freezing point for the element fermium?

2006-10-08 08:18:51 · 3 answers · asked by christine w 1

2006-10-08 07:45:18 · 2 answers · asked by Brain P 1

2006-10-08 07:37:13 · 8 answers · asked by Richard 1

2006-10-08 07:28:33 · 1 answers · asked by obinna p 1

i need to know for my kids home work!

2006-10-08 07:28:22 · 3 answers · asked by Hood 1

2006-10-08 07:12:42 · 5 answers · asked by Anonymous

2006-10-08 07:04:19 · 1 answers · asked by isknowledgereallyworthit 1

2006-10-08 06:45:56 · 9 answers · asked by Anonymous

please give me a number if larger than 118. recognized after 1993.

2006-10-08 05:52:19 · 1 answers · asked by Anonymous

2006-10-08 05:45:21 · 8 answers · asked by Anonymous

2006-10-08 05:41:30 · 2 answers · asked by Anonymous

if uknow the spdf configuration it would be very helpful

2006-10-08 05:20:33 · 2 answers · asked by goldengal 2

2006-10-08 04:22:35 · 5 answers · asked by Anonymous

2006-10-08 04:05:59 · 4 answers · asked by Anonymous

2006-10-08 04:03:32 · 4 answers · asked by afonso4real 1

2006-10-08 03:59:12 · 6 answers · asked by suhas 1

I need an exact answer, and a source.

2006-10-08 03:37:43 · 3 answers · asked by Che Revis 1

Thank you for all your help !

2006-10-08 03:17:25 · 6 answers · asked by Anonymous

2006-10-08 03:10:36 · 13 answers · asked by Anonymous

Not just what they are, but their significance. It doesn't even have to be a site. You can tell me in you own words if you wish.

2006-10-08 02:59:15 · 2 answers · asked by Anonymous

2006-10-08 02:21:39 · 4 answers · asked by M M L 1

2006-10-08 02:12:24 · 15 answers · asked by Anonymous

2006-10-08 02:10:15 · 4 answers · asked by Tarshall J 1

it is defind as work requied to increase the surface by 1sq.cm

2006-10-08 01:59:47 · 3 answers · asked by Anonymous

2006-10-08 01:30:50 · 4 answers · asked by Anonymous