It should be B because theories explain why something happens.
Answer:
c. they carry energy is the answer
Answer:
Closed as it can never be an open system for a number of reasons.
Answer:
- 58 kJ
Explanation:
The equation of the reaction is given as;
2NO2(g) → N2O4(g)
N2(g) + 202(g) → 2NO2(g) delta H = 67.7 kJ
Since NO2 is the reactant in the equation, we have to reverse this reaction. We now have;
2NO2(g) → N2(g) + 202(g) delta H = - 67.7 kJ
N2(g) + 202(g) → N2O4(g) delta H = 9.7 kJ
Since NO4 is the product in the equation, we don't have to do anything to this reaction.
Adding the two reactions;
2NO2(g) → N2(g) + 202(g) delta H = - 67.7 kJ
N2(g) + 202(g) → N2O4(g) delta H = 9.7 kJ
---------------------------------------------------------------- N2(g) and 2O2 (g) cancels out
2NO2(g) → N2O4(g) delta H = (-67.7 + 9.7) = - 58 kJ
Answer:
Volume of the helium will be 1.0L
Explanation:
To understand this question it is necessary to talk about 2 laws:
Charles's law that states: The volume of a given amount of gas held at constant pressure is directly proportional to absolute temperature.
Boyle's law that states: The volume of a given amount of gas held at constant temperature varies inversely with the applied pressure when the temperature and mass are constant.
Now, in the problem, if you have 4.0L of helium:
If the temperature is halved and the volume varies directly with temperature (Charles's law), the volume of helium will be 2.0L
Then, the pressure es doubled and as volume varies inversely with pressure (Boyle's law), the volume of helium will be halved, being 1.0L.
Thus, <em>volume of the helium will be 1.0L</em>