can you please explain step by step how to do these problems, I am really stuck
ID: 844026 • Letter: C
Question
can you please explain step by step how to do these problems, I am really stuck and I would really appreciate it.
1.) How would you prepare a 1L of a 1 M ethanol solution in water? you do not have an analytical balance available, only a 1 L volumetric flask and a 100 ml graduated cylinder. The density of ethanol is 0.789 g/ml
2.)describe how you would prepare 100ml of a single solution containing all of the following reagents at the designated concentrations.
a.) .1 M NaCl
b.) 0.06 M glucose
c.) 5% wt/volume alanine
d.) 1 mg/ml urea
Explanation / Answer
1. 100 mL solution contains 96 mL ethanol.
mass ethanol = 0.789 g/mL * 96 mL = 75.744 g in 100 mL solution.
46.07 g/mol / 75.744 g * 100 mL = 61.1 mL.
61 mL solution + 934 mL water = 1L 1M ethanol.
2. this caculation is usually based on molarity of stock solution that you have in
below example i have considered stock solution as
Glucose: 0.6M
NaCl: 1 M
alanine: Formula Weight: 89.09g/mole
Urea : 10mg/ml
for 1 L :
Glucose: 1:10 dilution = 100 mL
NaCl: 1:10 dilution = 100 mL
alanine: 5% g/1000mL = 50 g
Urea : 1/10 dilution = 100
for 100 mL:
Glucose 100*0,1 = 10 mL
NaCl: 100*0,1 = 10 mL
Ala: 50*0,1 = 5 g
urea 100*0,1 = 10 mL
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.