Question

Iodine monobromide and ammonia react to produce nitrogen triiodide and ammonium bromide.
(a) Balance the chemical equation for this reaction. (Use the smallest possible whole numbers. Enter 1 where appropriate. Do not leave any answer box blank.)
. IBr(s) + . NH3(g) . NI3(s) + . NH4Br(s)

(b) How many moles of ammonium bromide could be produced if you start with 0.750 moles of ammonia and excess iodine monobromide?
mol

Answer 1

For b just follow the steps is this example problem.
http://www.jiskha.com/science/chemistry/stoichiometry.html

For the equation it makes it easier if you show the arrow. Otherwise we must guess.
3IBr + 4NH3 ==>NI3 + 3NH4Br
A couple of notes. It is true that NH3 is a gas but little reaction will occur between gas NH3 and the solid IBr. Usually this is carried out in an aqueous solution, which dissolves NH3 readily, and the NH4Br then is in aqueous solution.