- Compound X is a white powder. It is a solid.
2. Questions.
- What is compound X?
- What will happen when compound X is heated and reacted with C20H14O4 (phenolphthalein – an acid-base indicator)? (1)
- How does compound X react with C20H14O4 (phenolphthalein)? (2)
- How does compound X react with water? (3)
- How does compound X react with hydro chloric acid (HCL)? (4)
3. Predictions.
- Compound X is calcium carbonate (CaCO3).
- (1) When compound X is heated and reacted with C20H14O4, the substance will turn pink.
- If a red litmus paper is dipped in the substance moistened with de-ionized water, it will turn blue.
- (2) When C20H14O4 is added to compound X, the product will be a white liquid, and no other change will occur. …show more content…
Next, compound X is heated in a beaker with the burner. Then C20H14O4 is added with a dropper pipet. Observations are made. (1)
Second of all, using a lab scoop, 0.4 g from compound X is put into a 50 ml beaker. It is weighted out with a digital balance. Then, the first step of the experimenting procedure is: with a lab scoop, a small amount of the substance goes into one of the test tubes. After that, phenolphthalein is added using a clean dropper pipet. Observations are made. This will determine whether compound X is a base, an acid, or a salt (neutral). (2)
Then, into another test tube a small amount of compound X is put using the same method. Next, water is added to the substance with a clean dropper pipet to see its reaction with water. Observations are made. (3)
Finally, the first step is repeated. Afterwards, hydro chloric acid (HCL) is added with a clean dropper pipet to the content. Observations are made. (4)
Additionally, a lit candle is put into the beaker with the rest of compound X in it. Subsequently, hydro chloric acid is added to the powder with a dropper pipet. This will determine what the released gas is (if there is any). (4)
7. …show more content…
Compound X is calcium carbonate (CaCO3). First of all, the prediction about the phenolphthalein turning the heated compound X into a pink liquid was supported, which means that it is not a base or an acid. The hypothesis was also backed up – compound X is a salt (calcium carbonate (CaCO3) =(heat)= calcium oxide (CaO) + carbon dioxide (CO2)). Additionally, the phenolphthalein did not change compound X’s color, so the prediction and the hypothesis were supported – compound X is a salt. Furthermore, the experiment with the litmus paper has the same results – both the prediction and the hypothesis were supported (the substance is a salt). Moreover, the prediction and the hypothesis about the dissolving of the powder in water were not supported. Compound X is insoluble (it has very low solubility). Lastly, both the prediction and the hypothesis about compound X’s reaction with hydrochloric acid (HCL) were supported. There is a reaction whose products are water and salt (and a gas – carbon dioxide). The reaction is as follows: X + 2HCL = H2O + CO2 + salt (metal of X+CL2). Due to the reason that this reaction needs two chloride molecules, the electrical charge of the metal of compound X should be +2. A number of sources show that therefore, compound X is calcium carbonate