1. assume that you weigh 0.4000g of sample that is pure NaCl andsubject it to th

Question

1. assume that you weigh 0.4000g of sample that is pure NaCl andsubject it to the procedure described in this lab. How many molesAg+ added in step                 3(please read at the bottom) of theprocedure is in excess of the moles of chloride? show thecalculations you used to answer this question.
                
                2. you are given a 1.00mL solution of 0.100M Cl- andtold to verify the chloride concentration by gravimetric analysis.1.00mL of 0.500M Ag+ is                 added to this solution and theresultant AgCl quantitatively precipitated. Based on theKsp expression, calculate the concentration of theCl-                 that remains in solution.
                
                LAB PROCEDURES STEP 3
                
                1. Assume your sample is all NaCl. On the basis of the sampleweight, calculate the amount of chloride and then the amount of0.2M AgNO3 required. Add                 that amount while slowlystirring and then ~5mL in excess. In order to avoid loss oraccidental transfer of silver chloride, use a separate stirring rodfor each                 sample.

Explanation / Answer

1.

The required reaction is NaCl + AgNO3 ------------> NaNO3 + AgCl (white ppt)

No of mole of NaCl= weight / molar mass = 0.4 g / (36.5 g/mol) = 11 mmol

From the above reaction 1 mol of NaCl required to precipitate 1 mol of Ag+

           So, 11 mmol of NaCl required to precipitate 11 mmol of Ag+

2. 1.00mL solution of 0.100M Cl- and 1.00mL of 0.500M Ag+

Its clear that excess Cl ion will not be there. All will get precipitate but excess Ag + will be there. So, concentration ?

3. You can calculate the amount of NaCl and AgNo3 by using molarity equation

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.