A chemistry graduate student is given 250. mL of a 1.50M hydrocyanic acid (HCN) solution. Hydrocyanic acid is a weak acid with K= 4.9 × 10 10. What mass of NaCN Sshould the student dissolve in the HCN solution to turn it into a buffer with pH = 8.84? You may assume that the volume of the solution doesn't change when the NaCN is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits.

Which of the following aqueous solutions are good buffer systems?. 0.34 M nitrous acid + 0.27 M potassium  nitrite 0.30 M ammonium  bromide + 0.31 M ammonia 0.15 M sodium  hypochlorite + 0.22 M hypochlorous acid 0.28 M nitric acid + 0.23 M sodium  nitrate 0.14 M hydrocyanic acid + 0.11 M potassium  cyanide   you can choose multiple choices if needed.

-5 A chemistry graduate student is given 450. mL of a 0.80M ammonia (NH,) solution. Ammonia is a weak base with K=1.8 × 10 °. What mass of NH¸Br should the student dissolve in the NH, solution to turn it into a buffer with pH =9.30? You may assume that the volume of the solution doesn't change when the NH,Br is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits.

4 F M -5 A chemistry graduate student is given 300. mL of a 1.10M benzoic acid (HCH,CO₂) solution. Benzoic acid is a weak acid with K-6.3 x 10. What mass of NaC6H₂CO₂ should the student dissolve in the HC H,CO₂ solution to turn it into a buffer with pH = 4.65? You may assume that the volume of the solution doesn't change when the NaC6H5CO₂ is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits. 0 Explanation 85°F Mostly sunny 4- 3 Check X $ 4 0 X с F5 % 5 5 E ▬▬ F6 6 Q Search F7 & 7 L F8 A * 8 9 F9 F10 ( 9 *- F11 © 2023 McGraw Hill LLC. All Rights Reserved. Terms of Use | Privacy Center | Accessibility Z ) 0 O *+ W F12 | 1 PrtSc + Insert = h Delete Backspace כ' נס 00- ►/11 Ar 1: 3/27 Lock