All elements in their standard states (oxygen<span> gas, solid carbon in the form of graphite, etc.) have a standard </span>enthalpy of formation<span> of </span>zero<span>, as there is no change involved in their </span>formation<span>.</span>
Answer : The correct option is (3) 500 K and 0.1 atm.
Explanation :
A real gas behaves ideally at high temperature and low pressure.
The ideal gas equation is,

where,
P = pressure of gas
V = Volume of gas
R = Gas constant
T = temperature of gas
n = number of moles of gas
The ideal gas works properly when the inter-molecular interactions between the gas molecules and volume of gas molecule will be negligible. This is possible when pressure is low and temperature is high.
Therefore, the correct option is (3) 500 K and 0.1 atm.
The nature of reactants, temperature, concentration, surface area and catalysts.
Answer: Because it's a combination of chemicals, vodka doesn't freeze at the same temperature as either water or alcohol. Of course, vodka will freeze, but not at the temperature of an ordinary freezer. This is because vodka contains enough alcohol to lower the freezing point of water below the -17°C of your typical freezer.
Explanation: .......