2007-06-26 06:37:50 · 4 answers · asked by heri623 3 in Science & Mathematics ➔ Chemistry
Calcium sulfate (a), ammonium chloride (b), and magnesium hydroxide (c) are all solids at room temperature and pressure when not dissolved in water. Water (d) and (e) can also be a solid, liquid, or gas at room temperature and pressure, though it will not remain a solid when it comes to equilibrium.
(Ortho)phosphoric acid is strange stuff that is nominally solid at room temperature but which has a melting point low enough to become a liquid on a really hot day. Phosphoric acid can also exist in a hydrated form that has an even lower melting point, though still high enough to be solid in a cool room. Or it can deliquesce - pull enough water out of the air to dissolve itself.
Magnesium hydroxide is a strong base which will completely dissociate into its Mg2+ and OH- ions when dissolved in water, or at least that small amount that will dissolve despite magnesium hydroxide's official status as insoluble in water. Pure water is neither an acid nor a base. Phosphoric acid is of course an acid and not a base.
Calcium sulfate solution is very weakly basic. The calcium ions dissociate completely and so do the first of the hydrogen ions from the bisulfate (HSO4-) ions, but the second hydrogen ions don't dissociate completely, leaving some undissociated HSO4- in solution and binding up a fraction of the hydrogen. This leaves a slight excess of OH- in the water, making the solution basic.
In ammonium chloride solution, the H+ and Cl- ions dissociate completely; but the NH4+ ions in solution bind with some of the OH- ions in the water to form NH4OH. This leaves an excess of H+ ions in the water, making it slightly acidic.
2007-06-26 07:24:09 · answer #1 · answered by devilsadvocate1728 6 · 0⤊ 0⤋
The first two answers above are completely wrong. A is the only solid among all the choices. All sulfates are soluble except for the sulfates containing, Ag, Pb, Hg, Ca, Sr, or Ba. Answers B, C, and F are all soluble in water and aren't solids. D and E are water so they can't be classified. The acids are D,E, and F. The bases are D and E. D and E are both an acid and base because water is an amphoteric substance (it can act as either a base or acid depending on what it is reacted with).
2007-06-26 14:43:42 · answer #2 · answered by swsu 2 · 0⤊ 2⤋
c is a base, and a and b are solids.
2007-06-26 13:55:27 · answer #3 · answered by Gervald F 7 · 1⤊ 0⤋
a, b, and c are all solids and c is the base
2007-06-26 14:01:17 · answer #4 · answered by Dr Dave P 7 · 1⤊ 1⤋