CHEM- 025
Mental Model-Draw a picture showing how the reaction can give both the precipitate and the supernatant seen in one of your reaction mixtures. In...
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I just need part B & C rest of the picture are just data that can help to answer those questions.




B. Mental Model-Draw a picture showing how the reaction can give both the precipitate and the
supernatant seen in one of your reaction mixtures. In other words, illustrate your reasoning in
question III.A using a picture of the reaction.
C. Predict what the limiting reactant should have been in each reaction mixture. Do this by assuming
the chemical equation you wrote in part I.B.3, page 24, is correct and then calculating which
reactant should run out first. Record the results of your calculations in the last column of the data
table on page 25. Show the calculations for mixtures #1 and #3 below.


there was
( supentune
since We
bigad and
IV. Conclusion
Summarize the data for and against the chemical equation you wrote for the reaction between Co(NO,),
and NasPO, in aqueous solution. In particular, explain how calculations involving weight data can be
used as evidence for or against a given reaction idea. Finally, do you feel your equation reflects what
nature is really doing? Briefly explain.


Pre-Lab Assignment: Study Appendix D.5 on filtration techniques.
Problem Statements: What is the reaction between Co(NO,), and Na, PO.?
Are all of each reactant consumed in a reaction? Why or why not?
I. Data Collection and Analysis: Qualitative
A. Dissolve a small amount (about 1 em') of solid cobalt nitrate, Co(NO,), in about 20 mL of distilled
water. Dissolve a similar amount of sodium phosphate, NasPO., in a second 20 mL of water. Describe
the appearance of each solution.
The cobyly nitrite is a clear but darker pinkish ligaid.
and it dissolved when mixed.
the sodium phosphate is a clear liquid with no color and
iz also dissolved in the Water chi Thoroughly (Save the mixture and two
B. Pour half of each solution into a third beat
solutions for later use.)
1. Describe the appearance of the mixture.
Now that It is mixed, The solution is avery vibrant
Purple color that looks slightly foggy ( solid ).
the ions are basically sepereply from each other.
2. Assuming the reaction involves the coming together of dissolved ions, what are the possible
identities of the solid formed in the mixture? Think up and carry out experiments which would
distinguish among all of the possibilities. Describe the results of these experiments.
Co ( Noz ) 2
+ act
( aq ) ( 9 )
( 4 )
( 5 )
Na cl
K P0 4
ca ( Nog) 2
3 -


II. Data Collection: Quantitative
A. Obtain 90 mL of stock Co(NO,), solution in a clean, labeled beaker. Obtain 60 mL of stock Na,PO.
solution in a second labeled beaker. Record the concentrations in the data table below.
Clean and distilled-water rinse four 100 ml beakers and label them 1-4. Into each beaker measure
20.0 mL of stock Co(NO,), solution. Measure various amounts of stock Na,PO, into each beaker.
The suggested amounts are:
5.0, 10.0, 15.0, and 20.0 mL
Mix each solution thoroughly and allow it to stand for at least 10 minutes, Calculate the masses of
salts added to each beaker and record these amounts in the table below.
B. Set up four filter funnels with filter papers and labeled collection beakers, Mix and filter each
reaction mixture from part II.A through a separate funnel, collecting its supernatant in a labeled
beaker. You are to collect at least 20 ml of each supernatant, clean of any precipitate. When this is
done, move on to part II.C.
Data Table
Concentration of stock Na, PO. solution
0.015 6
Concentration of stock Co(NO.), solution
0 + 018 3
mL stock
mL stock
Limiting Reagent
by Tests by Calculation
1.0 m / 20.0m1 0: 0789 0.36 6,14, DO4 2- 3 10
10 . OML 2 0AML 0. 16 69 01 3 6 6g Ng Pay 4, 7 5 x104
15 0ML 20+0 ml 0. 2349 0, 36Ag CO(/VO,), 7 13 x 10-4
20.OML 20.0-2 0. 3129 10 36 18 9,61/610)
G / 26/ 19


it add to Call, i ger - purplepit.
1 by tit
is add Na , Poed get purple pot
is LR
C. Describe the appearance of each of your supernatants. Divide each of the supercatants into two
parts. Test one part with a dropperful of Col NO,), and the other with a dropper full of Na.PO.
pollution. Summarize the results of theme tests below.
For the lomb, 5 nig g / 20 me the supernatents are
all clear, so no color or discince appearance.
the sml supernature is a light pink color and
is clear through out .
15.0 at
20.0 m
Tube 1: wedded
5.0 ML
10 oml
Tube I we addedeats carroll and it
we dividedinto
Tube I , wedadded
co (re, ), and it could purple.
and it tried in to forge got slightly darka
half land on, the tucked into cloudy purple /"
we added colno, 1. and it titbez . nothing butend
1 . Tube z: we added like it had a lotmode
stared the same wich would when we added
per mtheThem) pie .
be a he reaction.
clear color .
Tubear we added
"In test tube III. Data Analysis
14 Poy - clear ,
color .
2 we ambled wa Te A Explain the result of this testing of the supernatants. That is, explain what these results slow mount
and it t che/ mes , have happened in each reaction mixture, (For example, why can you form more precipitate from a no rex Cf, am
Cloudy Purple pre . superatante why contour that the previous page Clear caller.
2 0Ant Co(NO, ) , cal 839 colley
Imol Co( Nov),
Imc ColNOW .
182. 9415 1210
1 mol Co( 12)2 = 0.0 00 6 6 7 mot co ( P(4 ) ,
3 mal Co (Not )
5 . 0 m No po .
163.94 # 1
2 NY - PO .
163.94 170
15 AmL 1d, PO 2 4, 75 7 8 x 10 - 7. 13# + 10 nal (o ( P ),
- 5
20, 0 ml Na Po x 4, 75 78 x 10 = 9: 61#*x10 mat Co ( POW))


( aqp )
2 ) Nad + ca ( NO, ) ,
Bra No + each
We couldn't get purple color so it's not because
of No No.
( 4 )
( aq )
2 K, po. +3coc
( ag )
and we got the purple color so mixing co 720,
makes it to the one we want .
( ) For the solid collared in the funel it com
cobalt and phos phyte . for the liquid of the
bottom of the booker it contains sof um
and Nitrate .
D ) when we added cobalt Ni truce to the
Supermutant if made no changer to the minter.
a/zagg and then we added socliam phosphate to the minter
It turned purpel and t like our othe water.
. there was extra cobutt
the superinst.


F since We added sodium Phosphate to
the liqud and it turned purple this means
that there was coburt alread in them
y a picture
one of yo
liqud. ( supentune )
in a picture

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