Using standard reduction electrode potentials, calculate standard free-energy change at 25°C for the following reaction: 3Cu(s) + 2NO3-(aq) + 8H+(aq) → 3Cu2+(aq) + 2NO(g) + 4H2O(l).​

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 ?