Calculate the pH after 0.020 mol NaOH is added to 1.00 L of each of the solutions below. Answer with the appropriate number of significant figures. (a) 0.101 M HONH2 (Kb = 1.1 ✕ 10-8)
(b) 0.101 M HONH3Cl
(c) pure H2O
(d) a mixture containing 0.101 M HONH2 and 0.101 M HONH3Cl

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?