The most reliable way to determine if a new gas has formed is by "c. Medir la temperatura" or measuring the temperature.
1. When a new gas is formed, it can either absorb or release heat, causing a change in temperature.
2. By measuring the temperature before and after the gas formation, you can detect any significant changes, which indicate the formation of a new gas.
3. This method is reliable because it directly measures a physical property affected by the gas formation process.
Remember, safety is important when dealing with gases. Avoid options like "b. Hacer una prueba con fuego" (testing with fire) as it can be dangerous and unreliable.
