[NightHawkJJS]

I have to perform an experiment given the following information:

Title: Determination of Silver in an unknown

I. Record the sample number and accurately weigh your unknown silver sample.  Place the sample in a clean 1.0 ml volumetric flask and fill the flask to the mark with distilled water.  Mix the solution thoroughly.

II. Clean a buret with distilled water, rinse and fill the buret with the solution of the unknown.

III.  Dilute exactly 1.0 ml of the concentrate of potasssium thiocyanate (X.XXX M) to make exactly 25.0 ml of solution, mix thoroughly.  Fill a clean second buret with this standard solution of potassium thiocyanate.

IV. Drain into a 25.0 ml Erlenmeyer flask about 1.5 ml (accurately measured) of teh unknown silver solution, add 1.0 ml of 6 M nitric acid, 3 drops of ferric ammonium sulfate, and about 4.0 ml of distilled water.  Titrate this solution with diluted standard potassium thiocyanate solution to the first faint red tint in the solution.  Titrate a duplicate sample.  Calculate the percent silver in the unknown from your titration data.

V. Filter the precipitate formed in the reaction.  Wash with distilled water.  Wash with 5.0 ml of ethanol in 1 ml portions.  Air dry the product.  Weight and determin the percent of silver prsent in the original smaple, from your precipitation data.

VI. Calculate the percent difference for the percent silver.

The above information are the steps I must do I can not add anything else.

I need help to find out the following:
1. How do I dilute the solution in step III?
2. How do I calculate the percent silver in teh unknown from the titration data?
3. How do I calculate the percent of silver in the original sample, from the precipitation data?
4. How do I calculate the precent difference for the percent silver?

Thank You for your help