Adriatic Sea
(laboratory tests of water)
Ammonium Test
Into two test tubes we poured 5 ml of seawater. One was left untouched while in
the other reagents were instilled/poured: 12 drops of NH4-1 and one lab-spoon of
NH4-2. Then we shook the test tube and waited for 5 minutes. After that time we
instilled 4 drops of reagent NH4-3 and the solution became yellow. Now we had to
wait for 7 minutes. Conclusion – the solution is yellow – there is 0mg/l of NH+4.
Nitrite Test
Into two test tubes we poured 5 ml of seawater. One was left untouched while in
the other reagents were instilled/poured. At first, we instilled 5 drops of reagent
NO2-1, shook it and the color left the same. After that we put one lab-spoon of
reagent NO2-2 into the same test tube, shook it again and waited for 1 minute, the
color of water changed into faded-pink. Conclusion – there is 0mg/l of NO-2.
Nitrate Test
Two of the test tubes were rinsed with a water of subject, after that with the help of
syringe we poured 5 ml of water into each of them. Into one of the test tubes we
put two lab spoons of reagent NO3-1 and shook it for reagent to dissolve, then
waited for one minute, other test tube was left as it is. Then both test tubes were
inserted into comparator and colors were compared. Conclusion – there is 0 mg/l
of NO3.
Phosphate Test
Two of the test tubes were rinsed with a water of subject, poured 5 ml of water into
each of them. One of the test tubes was left as it is, while in the other we instilled 5
drops of reagent PO4-1 and put one lab spoon of reagent PO4-2 and shook it for
reagents to dissolve. Then both of the test tubes were put on the phosphate card
and then phosphate concentration was found. Conclusion – 0 mg/l of P04-3.
General Hardness Test
Test tube was rinsed with a water of subject and then 5 ml of water was poured
into it. We instilled 3 drops of reagent H-1 into the test tube and shook it for good
for reagent to dissolve. There were components of hardness, because we saw the
solution to become red. Later we took some titration solution H-Z into titration
pipettes and drop by drop instilled it into test tube, while rotating it. Theory said,
that color of the solution should have became green and later violet-grey, but it
didn’t happened, so we couldn’t determine the overall value of water hardness.
pH Test
Two of the test tubes were rinsed with a water of subject, after that with the help of
syringe we poured 5 ml of water into each of them. One of the test tubes was left as
it is, without any reagents, while in the other we instilled two drops of reagent
PTL-1 and shook it for reagent to dissolve. After that both of test tubes were
inserted into comparator and their colors were compared. The PTL was less than 8,
so this means the water of subject was alkaline.
Residual Hardness Test
Test tube was rinsed with a water of subject and then 5 ml of water was poured
into it. 3 drops of reagent H-1 were instilled into test tube. We shook it and the
solution became red, what leads to a conclusion, that density of water is more than
0,50.