1- Explain why :- i- boiled water tastes flat. ii-rainwater does not leave concentric rings when boiled. iii- a mixture of ice and salt serves as a freezing mixture. iv- air dissolved in water contains a higher percentage of oxygen. v- if distilled water is kept in a sealed bottle for a long time, it leaves etching on the surface.
Answers
Answer:
Explanation:
i)Many things can be dissolved in water, including air. When the water is boiled, the dissolved air leaves the water and the result is a flat taste. After boiling water, aerate the water by pouring it back and forth a few times between two containers. This adds air to the water and it will taste better.
ii)Rain water does not leave concentric rings when boiled because rain water does not contain dissolved solids. Air dissolved in water contains a higher percentage of oxygen because the solubility of oxygen in water is more than that of oxygen in air.
iii)The salted ice draws the heat out of the ice cream mix and it freezes. If you use ice without the salt, the ice cream will be cooled not be cooled to a low enough temperature to freeze. The salt lowers the melting point of ice low enough to be colder than the freezing point of the ice cream mix.
iv)Air dissolved in water contains high percentage of oxygen because solubility of oxygen gas in water is more than nitrogen and other gases present in the air. This is due to the small size of oxygen as compared to nitrogen due to which it easily gets trapped inside the vacant space between H2O molecules
v) If distilled water is kept in a sealed bottle for a long time, it leaves etchings on the surface of the glass because substances that are insoluble in water dissolve in trace amounts even small amounts of glass dissolves in water which will make etching on the glass surface.