I haven\'t done these calculations in some time. I tried #1 and #2, I dont think
ID: 1078274 • Letter: I
Question
I haven't done these calculations in some time. I tried #1 and #2, I dont think #2 is correct. Please help. The more explaination, the better. Thank you
1) The formula weight of NaCl is 58.44 g/mol. How would you make 300 mL of a 0.75 M solution of NaCl?
(VxCxMW) 0.3L x 0.75moles/L x 58.44g/mole = 13.149g
2) If your bottle of solid NaCl stated that the salt was only 90% pure, how much would you now have to weigh out to make 300 mL of a 0.75 M solution?
(VxCxMW) 0.3L x (0.90% x 0.75moles/L) x 58.44g/mole = ?
3) Starting with your 0.75 M solution of NaCl, how would you make 100 mL of a 25 mM solution of NaCl?
4) You are given a 10% (w/v) solution of NaCl – what is the concentration in Moles/L?
5) You have been given a solution of ATP of unknown concentration. You take 1 mL of the solution, and dilute to a final volume of 50 mL. The absorbance of this dilute solution at 259 nm is 0.570. What is the concentration of the original solution:
a) In mmoles/liter?
b) In mg/ml?
The Molar extinction coefficient of ATP is 15,400 l/mol cm.
The formula weight of ATP is 507.18 g/mole
Explanation / Answer
I haven't done these calculations in some time. I tried #1 and #2, I dont think