The correct answer is particle pollution.
Answer: 20.0 g of hydrogen chloride must simultaneously be formed
Explanation:
The balanced chemical reaction is :

According to the law of conservation of mass, mass can neither be created nor be destroyed. The mass on reactant side must be equal to the mass on product side.
Thus mass of reactants = mass of products
Given : mass of ammonium chloride = mass of reactants = 29.4 g
mass of ammonia = 9.4 g
mass of products = mass of ammonia + mass of hydrogen chloride
9.4 g +mass of hydrogen chloride = 29.4 g
mass of hydrogen chloride = 20.0 g
DeltaH formation = deltaH of broken bonds - deltaH of formed bonds
Broken bonds: tiple bond N-N and H-H bond
Formed bonds: N-H and N-N bonds
You also have to take note of the molar coefficients
deltaH formation = <span> [(N≡N) + 2 * (H-H)] - [4 * (N-H) + (N-N)]
= (945 + 2*436) - (4*390 + 240)
= 17 kJ/mol
The answer is 17 kJ/mol.</span>
D milk turning sour
the other options are physical changes