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a student takes about 2 ml ethanoic acid in a dry test tube and adds a pinch of sodium hydrogen carbonate to it.he reports the following observations:a)immediately a colorless and odourless gas evolves with a brisk effervescence.b)gas turns lime water milky when passed through it.c)gas burns with an explosion .d)gas extinguishes the burning splinter that is brought near it. which are the three correct observations?
It is a neutralisation (acid - base) reaction. Sodium Bicarbonate (baking soda) is a base, it reacts with the acetic acid (vinegar) to produce water (H2O) and Sodium Acetate. In the process it also evolves CO2 (carbon dioxide) as a product.
CH3COOH + NaHCO3 CH3COONa + H2CO3
         (acetic acid)  (sodium bicarbonate) (sodium acetate)
The  H2CO3 is not stable and breaks down quickly to form water and Carbon dioxide: ( H2CO3 H2O + CO2).

a)  CO2 is Colourless and odourless

b) It turns lime water milky.

c) CO2 Gas does not explodes Whereas Hydrogen blast with a pop sound.

d) carbon dioxide gas will extinguish a burning splint.

So a,b , d are correct.


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