Lab S-3
Solid Copper in Silver Nitrate Solution
Objectives 1a,8,9
lab objectives 1-4
BACKGROUND: In this lab you will determine the relationship
between moles of solid copper and silver. You will find the
mass of silver nitrate and prepare a solution of it, you will then
find the mass of copper before placing it into the solution of
silver nitrate and then observe what happens. At the end of the
experiment you will find the mass of the copper wire and with
that information you will be able to determine quantitative
relationships in the lab.
Remember that copper is an element made of only one
kind of atom, while silver nitrate is a compound made of silver
atoms bonded to a radical group called nitrate. Also remember
that a chemical reaction involves bond breaking and making (lab
6) and radicals stick together through think and thin, therefore
the radical will not break apart during this reaction.
PROCEDURE
1. Obtain a piece of copper, clean it with emery cloth and weigh
it. Record this mass on your data table.
2. Weigh out ABOUT 3.00 g of silver nitrate. Place this solid
into a small beaker and add 10 ml of distilled water. Mix until
all the solid is dissolved. WARNING: SILVER NITRATE
WILL TURN YOUR SKIN AND CLOTHING BLACK!!!
BE CAREFUL.
3. Pour the silver nitrate solution into an 18x150 test tube.
Rinse the beaker twice, with about 3-4 ml distilled water and add
this to the test tube also. Add distilled water to the test tube until
3/4 of the copper wire is covered. Stir and rinse off the stirring
rod into the solution as well.
4. Put the copper wire into the solution, add a 1-hole stopper
that fits the test tube and make sure the wire emerges through the
hole. Hint: look at the diagram below:
copper wire
5. Observe the setup for a few minutes and note any changes.
Let the setup sit overnight in the back cabinet as directed by
your teacher.
NEXT DAY
6. Now mass a piece of filter paper. Fold it as the instructor has
demonstrated and place it into the funnel and moisten it with
distilled water to allow it to adhere the glass.
7. Obtain the test tube from the back cabinet and again note
your observations. Record your observations in your lab write
up.
8. Remove the rubber stopper and shake off as many of the
crystals as possible. I wonder what they are? Using your plastic
spoon scrape as many of the adhering crystals as possible onto
the filter paper.
9. Set up a filtration system as you did in lab 7, be sure to know
the empty weight of the beaker collecting the filtrate. Pour all
the contents of the test tube into the filter paper, including the
crystals. Any crystals that stick to the sides of the test tube can
be rinsed out with the wash bottle of distilled water. Be sure to
collect the filtrate in a beaker. Remove the beaker under the
funnel when all the filtrate has moved through it.
10. Mass another beaker and place the filter paper with the
crystals into it. Place this beaker into the drying oven overnight.
Remember to write your name on the beaker.
11. Dip the copper wire into a test tube of acetone located at the
front desk and air dry.
12. Weigh the dry copper wire and record the mass in your data
table.
13. If time permits, carefully boil the liquid off. Do not cook
like Mrs. Foerster, it will burn. If this does occur, quickly take
the beaker, using beaker tongs, to the hood and turn it on until
the smoke subsides. Mass the beaker when dry and cool.
ring stand
1-hole
stopper
NEXT DAY
14. Remove the beaker from the oven, allow it to cool until you
can hold it in your hand and weigh it. Record this mass in the
data table. Return the crystals to the instructor for reclamation,
throw the filter paper away.
test tube clamp
18x150 test
tube
silver nitrate
solution
Lab S-3
Solid Copper in Silver Nitrate Solution
HINTS:
A data table consists of everything that has been measured in
lab, does yours? You should have data that allows you to
determine:
A. mass of copper used
B. mass of crystals made
C. mass of filtrate
QUESTIONS
1. Is mass conserved within experimental uncertainty?
2. What do the simple whole numbers represent in calculation
#10?
3. Recalling from lab 7 and question 1, if mass is conserved
what else is conserved?
CALCULATIONS
1. Find the mass of the filtrate.
2. Find the mass change in the copper wire.
4. Using the logic from question 3 write the formula of the
filtrate (stuff in the blue solution).
5. What causes the blue color in the solution after the reaction is
completed?
3. Find the mass of crystals produced.
4. Find moles of copper that reacted.
5. Find moles of silver produced.
6. Find the ratio: moles Ag
moles Cu
Write your answer in decimal form. Use sig. figs. to alleviate
uncertainty.
7. Find moles of silver nitrate used in the reaction.
8. Find the ratio:
moles Ag
moles silver nitrate
Write your answer in decimal form and use sig. figs.
9. Using the results from calculations 6 and 8 fill in the
coefficients in the following equation: (it is o.k. if they are not
whole numbers)
1 mole Cu (solid) + ____ mole(s) AgNO3 (solution) -------->
___ mole(s) silver (solid) + ___ mole(s) blue solution
10. From the video of the one armed magnet man and what you
know about chemical equations from lab 6 & 7, rewrite the
equation in calculation #9 using simple whole numbers.
11. Find the ratio:
sum of masses of products
sum of masses of reactants
6. What are the particles remaining in the water solution at the
end of the reaction, atoms, radicals or ions?