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Hello!
I don't know a lot of this but after doing just a bit of research I think the answer is either A. or C. but I think it is A.
Hope it helps?
Clap your hands each part word you eat and you will get your answer.
Calcium reacts gently with water to give hydrogen and calcium hydroxide, which is only slightly soluble, thus slows down the reaction.
It will be assumed that hydrochloric acid used is a dilute aqueous solution.
However, calcium reacts with hydrochloric acid to give calcium chloride which is readily soluble in water, and hydrogen, being a typical reaction of relatively active metals with acids.
Ca(s) + 2HCl(aq) -> CaCl2(aq) +H2(g) ↑ + heat
The clues that it is a chemical reaction could be:
- formation of a new substance, gaseous hydrogen
- disappearance of a metallic solid in the solution
- heat formed during the vigorous reaction.
As silver is below hydrogen in the electrochemical series, it will not be expected to react with dilute hydrocloric acid. (however, it dissolves in oxidizing acid such as nitric acid, but not displacing hydrogen as a product).
Answer:
Water for;
(a) NaCl
(b) HF
(c) (NH₄)₂SO₄
Hexane for;
(a) Octane
Explanation:
In chemistry there is a Rue of Thumb, "<em><u>Like Dissolves Like</u></em>" according to which polar compounds will dissolve in polar solvents and non-polar compounds will dissolve in non-polar solvents.
In given statement two solvents are given.
(1) Water: Water is a polar compound. It has a polar bond and a bent shape, hence has a net dipole moment.
(2) Hexane: Hexane is nonpolar because the electronegativity difference between the carbon atom and hydrogen atom is very less i.e. 0.4.
Therefore, polar solutes like NaCl (ionic), HF (highly polar) and (NH₄)₂SO₄ (ionic compound) will dissolve in water and Octane (C₈H₁₈ nonpolar) will dissolve in hexane respectively.
