Answer:
a.Low temperature
Explanation
Equation of reaction:
2NO2 <==> N2O4(g) ∆H = +ve
To cause the reaction to become darker brown means to produce more of NO2 gas. That is backward reaction.
Since the reaction is endothermic, decrease in temperature will shift the equilibrium position to the left thereby favouring backward reaction. This is in line with Me Chatelier's principle.
High pressure will rather favour forward reaction (it is not the right option).
Answer:
<em>so mass in gram=560grams</em>
Explanation:
number of moles=10moles
molar mass=56grams/moles
mass in gram of Fe=?
as we know that

<em>evaluating the formula</em>
<em>number of moles×molar mass=mass in gram</em>
<em>mass in gram=10moles×56grams/moles</em>
<em>mass in gram=560grams</em>
<em>i hope this will help you :)</em>
The partial pressure of the gas will be the total pressure minus the vapor pressure. 523.8-23.8=500mmHg. This makes sense due to the fact that the idea of partial pressures still works even with vapor pressure since vapor pressure is just the partial pressure of water vapor (23.8mmHg) in the container which is added to the partial pressure of hydrogen gas (500mmHg) to make a total pressure of 523.8mmHg.
I hope this helps. Let me know in the comments if anything is unclear.