Chemistry
In certain reactions a change of state is observed i.e. solid to liquid, liquid to gas etc. – State the change of state of the reactants – to give the respective products in each case. (a) C + 2S CS<sub>2</sub> (b) NH<sub>3</sub> + HCl ⇌ NH<sub>4</sub>Cl (c) 2H<sub>2</sub> + O<sub>2</sub> 2H<sub>2</sub>O (d)
Related Questions
A chemical reaction is generally accompanied by certain external indications or characteristics. These include change of –
(a) color
(b) state
(c) smell
(d) evolution of gas
(e) formation of precipitate
(f) evolution or absorption of heat.
With reference to change of color – state the change in color seen when the following are heated –
(i) copper carbonate
(ii) zinc carbonate
(iii) mercury [II] oxide
(iv) lead [IV] oxide
Give a balanced equation for addition of iron to copper [II] sulphate solution. State the change in color seen.
In certain reactions a change of smell is observed. Give two examples from daily life of the same.
In certain reactions an insoluble solid called precipitate is formed. State the colour and name of the precipitate formed in each of the following reactions involving addition of:
(a) Dilute hydrochloric acid to silver nitrate
(b) Iron [II] sulphate to sodium hydroxide
(c) Iron [III] chloride to ammonium hydroxide
(d) Copper [II] sulphate to sodium hydroxide
(e) Lead nitrate to ammonium hydroxide