can you please explain step by step how to do these problems, I am really stuck

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

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