Aand b are powders, a is insoluble while b dissolves to give a ph 3 solution. mixing a and b gives bubbles or effervescence and a clear solution.
a) which is the acid?
b) if the other substance is a carbonate, name the gas given off.
c) even though a is insoluble a clear solution is given off, explain why.

I think it is a nitric acid

a) B is an acid

b)carbon dioxide

c) it is salt of the acid

Explanation:

a)  B dissolves to produce an acid. An acid, according to the Bronsted-Lowry theory, dissolves in an solution to give an acid solution of a pH less than 7 on a pH scale.

b) carbonates gives a gaseous effervescence. The gas given off is carbon dioxide

c) The solution is a salt of an acid. This is in an aqueous solution.

n2(g) + 3h2-> 2nh3(g)   this is the balanced equation

note the mole ratio between n2, h2 and nh3.   it is 1 : 3 : 2   this will be important.

moles n2 present = 28.0 g n2 x 1 mole n2/28 g = 1 mole n2 present

moles h2 present = 25.0 g h2 x 1 mole h2/2 g = 12.5 moles h2 present

based on mole ratio, n2 is limiting in this situation because there is more than enough h2 but not enough n2.

moles nh3 that can be produced = 1 mole n2 x 2 moles nh3/mole n2 = 2 moles nh3 can be produced

grams of nh3 that can be produced = 2 moles nh3 x 17 g/mole = 34 grams of nh3 can be produced

note:   the key to this problem is recognizing that n2 is limiting, and therefore limits how much nh3 can be produced.

the answer is a and have a great day