A solution of NaOH in water is:(i)golden yellow in colour (ii) pale green in colour (iii)sky blue in colour (IV)colourless (PLs experts and urgently with reasoning)?
Sodium hydroxide solutions are absolutely colourless.
Sodium hydroxide is usually sold as white pellets (or fine white, hygroscopic powder), that dissolve in water to give a colourless solution. They are odourless as well. This is part of the reason why conc. hydroxide solutions are dangerous. When you get splashed with it you don't know that you have been splashed. This is in contrast with an acid burn; when you get splashed with acid it hurts then and there. When you get splashed with hydroxide, and don't wash it off immediately, it hurts later.