gravimetric analysis to identify an unknown oxide of copper. In this experiment,

Question

gravimetric analysis to identify an unknown oxide of copper.

In this experiment, you will identify an unknown as either sodium carbonate ("soda") or sodium hydrogen carbonate (sodium bicarbonate or "baking soda"). The method will involve the reaction of the unknown with excess hydrochloric acid, which will occur according to one of the two following reactions:

Na2CO3(aq) + 2HCl(aq) 2NaCl(aq) + CO2(g) + H2O(l)

NaHCO3(aq) + HCl(aq) NaCl(aq) + CO2(g) + H2O(l)

Both reactions produce the same products, but not in the same proportions. Thus, gravimetric analysis of the solid product, NaCl, can be used to determine the identity of the unknown.

***I need to answer this question

1) What are the boiling points of your reaction products and the solvent they will be dissolved in? [Consult a reference book like the CRC Handbook of Physics & Chemistry.] Explain why this information is critical to the design of this experiment.

Explanation / Answer

The boling points of the products are

NaCl = 1413 oC

CO2 = -78.5 oC

H2O = 100 oC.

The sodum chloride dissolves in water and its boiling point is 100 oC.

Siginificance of above values:

For gravimetric analysis, we need to isolate the amount of pure NaCl produced in the above given reactions. For this we need to have estimation of boling points of other products and solvent. As evident from above boiling point values NaCl dried can be isolate by heating the temperature to 100 C.

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