Q23 of 27 Page 1

From an experiment to study the properties of acetic acid. Answer the following questions:

a) Name the substances which on an addition to acetic acid produce carbon dioxide gas. Give relevant chemical equation for the above?


b) How is CO2 gas tested in the laboratory?

a). When acetic acid is made to react with sodium bicarbonate or sodium carbonate, carbon dioxide a colourless, odourless gas would be produced as the product. The reaction between sodium bicarbonate and acetic acid is as follows:

NaHCO3 + CH3COOH → CH3COONa + CO2 + H2O


b). When the carbon dioxide is made to pass through lime water, lime water turns milky in appearance. This is due to the formation of calcium carbonate in the solution. The reaction is as follows:


CO2 + Ca (OH) 2→ CaCO3 + H2O.


The carbon dioxide should not be passed for a long duration as the white precipitate of Cacaogets dissolved in excess of CO2 to form calcium hydrogen carbonate.


Ca (OH)2 + 2CO2→Ca (HCO3)2


More from this chapter

All 27 →
21

(i) With the help of an activity, explain the method of inducing an electric current in a coil with a moving magnet — State the rule used to find the direction of electric current thus generated in the coil.

(ii) Two circular coils-1 and coil-2 are kept close to each other as shown in the diagram.Coil-1 is connected to a battery and key and coil-2with a galvanometer. State your observation in the galvanometer:



a) When key k closed; (b) when key k is opened; Give a reason for your observations.


OR


Name a device which converts mechanical energy into electrical energy. Explain the underlying principle and working of this device with the help of a labelled diagram.

 22

When a few drops of phenolphthalein are added to a dilute solution of sodium hydroxide a pink colour is produced. What will be the colour of the final mixture when an excess of HCl is added to it? (justify your answer)

OR


Arrange the metals iron, magnesium, zinc and copper in the increasing order of their reactivity. What will be the two observations made by the student when iron filings are added to the copper sulphate solution?

 24

When observed under high power of the microscope, ‘chain of buds’ is visible in the microscopic view. In which organism can it be observed? Explain the process.

OR


In the experimental set up on ‘CO2 is released during respiration,’ if one forgets to keep the vial with KOH in the conical flask, how will the result vary? Give details.

 25

You soak seeds of bean and observe them after 2-3 days. What will be your observations?