Gravimetric Analysis: the Determination of Phosphorus in Plant Food

After added, pick up the beaker and swirl it around lightly for a short period of time.

Weigh the nut, the aluminum cup, and the test tube clamp all together. Record the total

Fill the rest of the container almost to the top with water and let the mixture separate.

11.Pour the mixture mixed with water over the filter paper so that the sand remains on top of the paper and the soluble salt water will go through into the beaker

Place 100 ml of distilled water in a 250-ml (or 400-ml) beaker. Add 1.26g of oxalic acid dihydrate (H2C2O4.2H2O) and 1 ml of concentrated ammonia. Stir the mixture until the solid has dissolved completely.

XII. Take the 250 ml beaker to your lab bench. Set up a gravity filtration with a plastic funnel, folded wet filter paper, and an Erlenmeyer flask. Pour the content in the 250 ml beaker slowly through the filter paper. Wash the filter paper with deionized water. Dispose of the filtrate in the proper labeled waste container.

2) Rinse the solid with about 30 mL of distilled water and decant the liquid from the solid. It is critical that as little solid as possible is lost during this process. Repeat the rinsing two or three times.

After cooled down a little, mix with a glass stirring rod until sample is uniform in texture and appearance, then re-weigh the sample.

Step 2: Mix 80 mL of water into the cornstarch. Make sure the consistency of the mixture is smooth.

Measure 75 mL of a liquid/substance into a cup. Place liquid/substance on weighted scale to calculate the density. Record results on a piece of paper. When finished finding the density, pour the liquid/substance into beaker. Repeat steps 1-3 with 4 other

We will then dissolve it in 50ml distilled water by swirling and use a 125ml volumetric flask.

The solution is made up to the graduation mark with 50cm3 of 2.0M H2SO4. The conical flask is stoppered and inverted 10 times to ensure sufficient mixing. Water is sprayed around the glass surface to minimize chances of unwanted Fe residues.

We also became aware of how to perform mass measurements using three different balances. Upon weighing the penny we found that the results from all the scales where within 0.08g of each other. The results from weighing 2 pennies was not much different with a deviation of 0.04g between all three scales. For the glass beaker we obtained two results as the maximum on the analytical balance is 200g, the object we weight was well over this weight. We did however get to compare the top loader and the triple beam balances. The difference in these two scales was 0.16g. Because we do not have a true mass value for the penny we cannot prove that the mass measurements are accurate although they are precise as we received the same value each time we put the object on the balance. When we performed the volume measurement we dispensed 10-ml in to all three measuring devices using the pipet. We found that on the 10-ml graduated cylinder the colored solution passed the 10-ml line. Similarly, on the 50-ml beaker the solution was over 0-ml yet under 20-ml which left us inconclusive results. Lastly the 50-ml graduated cylinder measured 10.1ml which was the most accurate of the three measuring devices. Ultimately the 50-ml beaker and the 10-ml graduated cylinder proved not to be accurate which is supported by the data. The only measurement that proved to be more

Stack two clean, dry foam cups on top of each other. Find the mass and round it to the nearest hundredth of a gram; record the data.

We closed the bottle and mixed by inverting gently until the precipitate and the reagent completely dissolve. Afterwards we opened the bottle and poured 20ml of the liquid into a small flask then added 8 drops of starch indicator solution to it. We grabbed a bottle of sodium thiosulfate and grabbed the titrator (the thing that looks like a shot/needle). We stuck the tip of the titrator into the hole of the bottle of sodium thiosulfate and inverted the bottle to start filling the titrator. We made sure that the liquid in the titrator had no air bubbles then put the tip of it into the hole of the glass flask.