What is a chemical formula

Answer asap need it by wednesday morning calculate the ph of 0.02m hcl best answer will be brainliest

40dm3 of gas at 760 torr are heated from 5°c to 50°c what is the new volume

Before it was launched, a helium-filled balloon had a pressure of 201 kpa at a temperature of 27°c. at an altitude of 15,000 m, the pressure had decreased to 2.5 kpa and the temperature had dropped to -14 °c. the volume of the balloon increased to 59.3 m3. what is the original volume of the balloon? 13 m3 0.85 m3 0.077 m3 1.17 m3