Which of the following is the best example of an open system? (2 points)
question 1 options:

1) a car engine

2) our universe

3) a greenhouse

4) an insulated gas cylinder

A50.0g sample of liquid water at 0.0 c ends up as ice at -20.0 c. how much energy is involved in this change?

The activation energy for the reaction no2(g)+co2(g)⟶no(g)+co(g) is ea = 300 kj/mol and the change in enthalpy for the reaction is δh = -100 kj/mol . what is the activation energy for the reverse reaction?

Which of the following is a physical property flammability heat of combustion solubility and toxicity