☰
Control and Coordination
A student adds a few drops of ethanoic acid to test tubes X, Y and Z containing aqueous solutions of sodium chloride, sodium hydroxide and sodium carbonate, respectively. If he now brings a burning splinter near the mouth of the test tubes immediately after adding ethanoic acid in each one of them, in which of the test tube or test tubes the flame will be extinguished?
X and Y
Y and Z
X and Z
Only Z
D.
Only Z
The correct option is D.
The chemical reaction involved is:
Test tube X:
CH3COOH +NaCl ---> No reaction
Test tube Y:
CH3COOH +NaOH ---> CH3COONa + H2O
Test tube Z:
2CH3COOH + Na2CO3 ---> 2 CH3COONa + CO2 + H2O
Thus, the flame will be extinguished when test tube Z is brought near a burning splinter. Carbon dioxide is evolved in this reaction and it does not support combustion.
Sponsor Area
Choose the olfactory indicators and give their characteristics: red cabbage extract, onion, vanilla extract, litmus, clove oil.
Take 5 ml hydrochloric acid in a boiling tube or a conical flask. Add a few pieces of zinc granules to it.
(a) What do you observe on the surface of zinc granules?
(b) Name the gas evolved.
(c) What happens when the above gas is passed through soap solution?
(d) What happens when a burning candle is brought near the gas filled tube?
Sponsor Area
Sponsor Area