In a chemistry experiment, the total energy contained in a system is 45 joules. After the system undergoes a chemical reaction, the total energy in the system is 39 joules. Which of the following statements is true?

A. The surroundings lost 6 joules.

B. The surroundings gained 6 joules.

C. The surroundings did not gain or lose any energy

D. This is impossible: a system cannot lose energy

In vapor-liquid equilibrium in a binary mixture, both components are generally present in both phases. how many degrees of freedom are there for such a system? the reaction between nitrogen and hydrogen to form ammonia occurs in the gas phase. how many degrees of freedom are there for this system? steam and coal react at high temperatures to form hydrogen, carbon monoxide, carbon dioxide, and methane. the following reactions have been suggested as being involved in the chemical transformation: