Introduction
I finely crumbled a given bar of school white chalk with a mortar and pestle into a fine homogeneous powder without lumps. Then I dissolved the substance in 50 mL of ordinary drinking water and stirred vigorously. The calcium-gypsum mixture, which forms the base of the chalk, was not completely dissolved in water, and once the equilibrium in the glass had settled, I filtered the mixture entirely through filter paper. The clear water was collected as a filtrate in a beaker under the filter paper, while the wet chalk powder, which had acquired an intense gray hue, was in the filter. After the collected “purified” water was boiled on the stove at 95-100°C, all the liquid evaporated, and white sediment grains remained at the bottom of the beaker.
Checking with an Indicator
In the second part of the work, a mixture of 10 g of solid calcium hydroxide and 50 mL of drinking water in a beaker was initially created. I closed the beaker tightly with a rubber stopper and stirred it vigorously. The mixture was passed through filter paper, resulting in “purified water” collected in a flask under the filter. Additionally, a sterile flask with pure drinking water, devoid of impurities, was created. I added two drops of phenolphthalein indicator to each of the two flasks, after which visual changes were observed, if appropriate.
Data
The presence of minerals in the composition of the filtered water was observed on the fact of the two procedures performed. The boiling allowed all excess moisture from the beaker to evaporate, but this evaporation left a fine pale murky powder of calcium-gypsum on the bottom. In the second part of the work, phenolphthalein added to pure water showed no result: the color of the solution did not change. However, the addition of clear phenolphthalein to the water collected after filtration resulted in a faint violet hue inside the flask.
Results
The present work tested the solvent property of water and its ability to transfer minerals from a solid to a liquid state. Some of the chalk powder remained at the bottom of the plate after water evaporation indicates that not all of the chalk was left in the filter. To put it another way, some of the sediment was dissolved by the water molecules, then returned to solid form when all the water was evaporated. At the same time, the formation of a purple coloring of the filtered water was a sign of a slightly alkaline water environment. This probably indicates that some of the calcium hydroxides were converted to a liquid form, which gave a reaction to the indicator.
Interpretation
In contrast to soil, water has better solubilizing properties, and therefore its use proves to be an advantage. Thus, hydroponic horticulture seems to bring better results for the agricultural industry because water actively brings minerals that have been dissolved in it from fertilizers to the plants. Water is a kind of conductor that creates the opportunity for substances to penetrate the plants by root pressure, and this effect is probably stronger than in the presence of solid soil. However, more research is needed to verify this, including the actual growing of plants on hydroponic systems and soil to track the dynamics. In addition, it is interesting to know which fertilizers prove to be most effective in such systems.
Conclusion
The proposed hypothesis was true, fully proven by the tests performed. Water did indeed prove to be an excellent solvent, as it could dissolve even solid, seemingly insoluble substances. This was confirmed in two ways, ensuring that systematic error was minimized. This work was helpful for me: I learned about hydroponics and its advantages over classical gardening.