Ethyl propanoate can be prepared by the reaction of ethanoic acid with propanol. b) ethanoic acid with isopropanol. c) ethanoyl chloride with propanol. d) propanoyl chloride with ethanol. e) acetic anhydride with propanol.

Option D

Explanation:

Ester is prepared by esterification reaction between Carboxylic acid and alcohol

And from acid derivatives like acid chloride, anhydride & amide etc.

Here A gives propyl ethanoate by Esterification

B gives isopropyl ethanoate by Esterification

C gives propyl ethanoate by Acylation of alcohol

D gives ethyl propanoate by Acylation of Alcohol

E gives like C.

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.

if you mean hydrogen and oxygen then water is the product