Question

A 1.00 liter solution contains 0.40 moles nitrous acid and 0.31 moles potassium nitrite. If 0.15 moles of hydrobromic acid are added to this system, indicate whether the following statements are true or false. (Assume that the volume does not change upon the addition of hydrobromic acid.) DA. The number of moles of HNO, will increase. B. The number of moles of NO, will increase C. The equilibrium concentration of H,0" will increase D. The pH will decrease. E. The ratio of [HNO,]/[NO2] will remain the same.

Answer 1

mitous acid (HN02) and INO2 is a buffer solution. It is acidic bigger HNO2 + oH → KNG tho PH= plat log [KNOL] Luld HNO2 tkoH KNG & Ho 0:31 0:40 after addition of 0.15 moles of HBr , it reacts with Salt Knus to convert HNO2 & Kby. So increase the moles of HNO2 astee addition of AB occurs and decrease the moles of KNO2. New HNo molef = initial molest moles of HRY = 0.40 7.0.15 = 0.55 new knog moes initial noted - moles of HBV = 0.39-0.15 = 0.16

A. True moles of Hng increases B. False moler of was decreases true c. Elle Но, — 4 + но HBY add HBritt it reacts with no, and convert to Hnos. no change it too confentation. More Hnos dissolve in water, increase the concentrations of Hool D. True Initial pH= pka + Log [kNo] = pkatlog (0.31) [Hng] 0.640) = pllat log (0.715) = pka- 0.11 after addition of HBI PH= prat log (0.16) = pla+log/0.29) = pka -0.54 Comored two phs, aftee addition of her pH values 78.55) decreases.

E. False - BoB 0.40 = 1.29 [Anas] Ing] L mateslet neoted at initial 0:16