tolong bantuin dong no 37-40

39. molalitas = gr/mr × 1000/v
= 18/180 × 1000/400
= 1/10 × 10/4
= 10/40
= 1/4
= 0.25 (C)

40. Fraksi mol NH3 (Ammoniak)
= n amoniak / n ammoniak + n air
= 0.2 / 0.2 + 0.8
= 0.2 / 1
= 0.2 (B)