What liquid is used to safely store acetylene gas at pressures above the danger point?

Acetone is the correct choice for safely storing acetylene gas at pressures above the danger point. Acetylene is a highly flammable gas that, when compressed, can become unstable and pose significant safety risks. To mitigate this hazard, acetylene is stored in a solution of acetone within high-pressure gas cylinders. Acetone serves as a solvent that allows acetylene to be dissolved at pressures that are much higher than what the gas itself can be safely contained without the risk of explosive decomposition.

The use of acetone in this context ensures that the gas remains stable and reduces the likelihood of dangerous reactions that could occur in its pure form under high pressure. This method of storage is a standard practice in the welding industry for safely handling acetylene, thus allowing it to be transported and utilized in various applications without the inherent dangers of storing the gas alone under high pressure.