View Full Version : What is the Molarity
zezo254
Apr 23, 2010, 02:19 AM
What is the Molarity of 1.00 ppm of Fe2+ prepared from ammonium sulphate (FeSO4.(NH4)2SO4.6H2O).
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zezo254
Apr 23, 2010, 03:26 AM
What is the volume required to prepare 1.00 L of 100 x 10-3 M of Cl- out of 250 ppm stock solution of Mg2+ as MgCl2.
zezo254
Apr 23, 2010, 03:28 AM
Urine sample has a chloride concentration of 150 mN (meq/L). If all of the chloride in urine is assumed to be as NaCl; what is the concentration of NaCl in g/L.
Please help me
zezo254
Apr 23, 2010, 03:30 AM
Tris(hydroxymethyl)aminomethane (THAM) is a weak base frequently used to prepare buffers in biological work since the corresponding pKa is 8.08, which is near the pH of the physiological buffers. What is the weight of THAM required to prepare a 1 L buffer with pH 7.40 and 100 mL of 0.50 M HCl.
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zezo254
Apr 23, 2010, 03:32 AM
What is the pH of the buffer produced by mixing 5.0 mL of 0.1 M NH3 with 10 mL of 0.020 M HCl. Determine the pH after 1:1 dilution or addition of 1mL of 1.0 mM NaOH or HCl.
Curlyben
Apr 23, 2010, 03:33 AM
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zezo254
Apr 23, 2010, 07:23 AM
Please Help me to solve these questions
zezo254
Apr 23, 2010, 03:00 PM
Thank you for taking the time to copy your homework to AMHD.
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Unknown008
Apr 23, 2010, 11:17 PM
We can give help, but what is your input?
Have you given those questions a try? If so, what have you done? Post them, then, the help will come.
zezo254
Apr 24, 2010, 06:22 PM
But what is your input?
These questions fully
Have you given those questions a try?
No I am new user.
zezo254
Apr 24, 2010, 06:23 PM
Urine sample has a chloride concentration of 150 mN (meq/L). If all of the chloride in urine is assumed to be as NaCl; what is the concentration of NaCl in g/L.
please help me
Stock solution contains 250 mg Mg per 1000ml = 250ppm
Molecular mass of Mg Cl2 = 95.211
250 mg of Mg is contained in 95.211 / 24.3 times 250 mg of Mg Cl
= 979.5 mg Mg Cl2
which contains (35.45*2 / 95.211) times 979.5 mg of Cl
=729.3 mg of chlorine in 1000ml = 729.3 ppm Cl = (729.3/1000) / 35.45 molar
=0.0206 molar in Cl-
Dilution...
Assuming 1.00 x 10^-3 M is intended, not 100 x 10^-3..
(sign for indices is on the 6 key)
0.0206 M => 0.001 M
0.0206 / 0.001 = 20.6 ml of stock solution required, diluted to 1L
zezo254
Apr 24, 2010, 06:25 PM
Stock solution contains 250 mg Mg per 1000ml = 250ppm
Molecular mass of Mg Cl2 = 95.211
250 mg of Mg is contained in 95.211 / 24.3 times 250 mg of Mg Cl
= 979.5 mg Mg Cl2
which contains (35.45*2 / 95.211) times 979.5 mg of Cl
=729.3 mg of chlorine in 1000ml = 729.3 ppm Cl = (729.3/1000) / 35.45 molar
=0.0206 molar in Cl-
Dilution...
Assuming 1.00 x 10^-3 M is intended, not 100 x 10^-3..
(sign for indices is on the 6 key)
0.0206 M => 0.001 M
0.0206 / 0.001 = 20.6 ml of stock solution required, diluted to 1L[/QUOTE]
zezo254
Apr 24, 2010, 06:26 PM
Stock solution contains 250 mg Mg per 1000ml = 250ppm
Molecular mass of Mg Cl2 = 95.211
250 mg of Mg is contained in 95.211 / 24.3 times 250 mg of Mg Cl
= 979.5 mg Mg Cl2
which contains (35.45*2 / 95.211) times 979.5 mg of Cl
=729.3 mg of chlorine in 1000ml = 729.3 ppm Cl = (729.3/1000) / 35.45 molar
=0.0206 molar in Cl-
Dilution.....
Assuming 1.00 x 10^-3 M is intended, not 100 x 10^-3..
(sign for indices is on the 6 key)
0.0206 M => 0.001 M
0.0206 / 0.001 = 20.6 ml of stock solution required, diluted to 1L[/QUOTE]
This answer for What is the volume required to prepare 1.00 L of 100 x 10-3 M of Cl- out of 250 ppm stock solution of Mg2+ as MgCl2.
Unknown008
Apr 25, 2010, 02:05 AM
Ok, that's better.
Only the last part.
0.0206 mol Cl- is contained in 1000 mL
You need 0.001 mol of Cl-, diluted to 1 L.
0.0206 mol => 1000 mL
1 mol => 1000/0.0206 mL = 48600 mL
0.001 mol => 48600 * 0.001 = 48.6 mL
So, you need 48.6 mL of solution, diluted to 1 L.
Is it okay? :)
zezo254
Apr 25, 2010, 03:43 PM
I do not want your comments
If you can not solve any question do not write anything
OK
Unknown008
Apr 26, 2010, 07:19 AM
If you don't want any help, then it's up to you. I don't think anyone will come and answer your questions. It seems you didn't read the announcements about homework questions.
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