Calculate the mass of ammonia salt that would remain if the solution were evaporated to dryness. When sulfuric acid reacts with ammonia solution an ammonium salt is produced. 2.5M * 0.025L/2=x/132 =4.125g
You need to do a better job of posting questions. If the question is to calculate the grams ammonium salt starting with 25 mL of 2.5M H2SO4 the number you have isn't right. If it is 25 mL of 2.5M NH3 the answer is 4.129 which I would round to 4.1g to two significant figures. That's all you show in 0.025 and 2.5.
