An insulated 8m* rigid tank contains air, modeled as an ideal gas, at 600kpa and 400k. a valve connected to the tank is opened and air is allowed to escape until the pressure drops to 200kpa. the air temperature is held constant during the process by an electric heater placed in the tank. determine the electrical energy supplied to the air during this process. internal energy of the initial air is u = 286.1 6hĺ kg ; the enthalpy of the exiting air is hvit400.98hj/ kg

Explanation:

We assumes that all the electrical energy produced will be converted into the heat energy.

    Electrical energy input = Heat energy absorbed by object = Heat energy required = Q

As,        Q = U - W

                = U - RT

Since, it is given that U = 286.1 kJ/kg, is 600 kPa, is 200 kPa, and T is 400 K.

Therefore, putting these given values into the above formula is as follows.

          Q = U - RT

              =

              =

              = 412.27 kJ/kg

Thus, we can conclude that the electrical energy supplied to air is 412.27 kJ/kg.

3 hours because it is a decent distance.

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.