Which of the following has an extensive reaction with water? Please explain why?

Question

NH3
HNO3
Na2S
HCN

Answer 1

Without consulting any reaction energy tables, my money's on HNO3. Nitric acid is one of about a half dozen really strong acids and will give off a tremendous amount of heat when dissolved in water. I don't think any of these will actually react with water, but nitric acid will certainly dissolve the most violently. If you have access to reference tables, you'll want to look up reaction enthalpies, or dissolution enthalpies.

Of the compounds you listed, Ammonia (NH3) is a weak base that will not do anything special when added to water, Nitric Acid (HNO3) is a very strong mineral acid that dissolves exothermically, Sodium Sulfide (Na2S) is an ionic salt that should dissolve without any fireworks, and Hydrogen Cyanide (HCN) is a somewhat weaker acid that I would expect to give off less heat than HNO3 when dissolved in water.

Answer 2

i had to say that against all odds NH3 is the one you´re looking for
HNO3 is an acid so it just will dissolve in water this gives you heat (add it slowly or it will splash all around, this is no t nice)but not a real chemical reaction other way
Na2S is truly a salt so it will break slowly cause it´s nearly not soluble in water (weird for sodium usually very soluble)
HCN has teh same thing that HNO just that HCN is much more covalent so it is more weak
on the other side NH3+H2O--- NH4+ and OH- meaning this will actually capture proton (H+) and react with water rather than moving the equilibrium (Kw) as other acids and alkalis do

Answer 3

Na2S will not extensively react with water. It is a metal salt that will merely desolve, similar to NaCl (tablesalt).


HCN will react with water to form an acid. A solution of hydrogen cyanide (HCN) in water is called hydrocyanic acid or prussic acid. Pure hydrogen cyanide is a colorless, very poisonous, and highly volatile liquid that boils slightly above room temperature at 26 °C, thereby generating hydrogen cyanide gas. Hydrogen cyanide has a faint, bitter, almond-like odor that some people are unable to smell due to a genetic trait. Hydrogen cyanide is weakly acidic and partly ionizes to become the cyanide ion CN– in aqueous solution, resulting in a colorless volatile liquid with the typical hydrogen cyanide odor.

Answer 4

Na2S because na in group 1a, and just because i know potassium is the most volital in water.

Answer 5

Any of your rare earth metals will react due to the low valence.

You can figure it from there.