Can someone please answer this with explanation?

Gymnast always perform on padded mats. how does the mats protect the gymnast

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

How many moles of potassium hydroxide are needed to completely react with 2.94 moles of aluminum sulfate according to the following equation: