KOH was added to a 6.75 x 10-3 M solution of HNO3 so that the end solution has a pH of 2.333. What is the positive difference in concentration of [H30+]? A) 4.65 x 10-3M
B) 5.25 x 10-3 M
C) 2.10 x 10-3M
D) 2.10 x 10-4 M
E) 3.15 x 10-3M​

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 ?