Answer : The assumptions appears reasonable for the isothermal process is,
and 
Explanation :
First law of thermodynamic : It states that the energy can not be created or destroyed, it can only change or transfer from one state to another state.
As per first law of thermodynamic,

The expression for internal energy is:

The expression for enthalpy is:

where,
= internal energy
q = heat
w = work done
n = number of moles
= specific heat capacity at constant volume
= specific heat capacity at constant pressure
= change in temperature
As we know that, the term internal energy and enthalpy is the depend on the temperature and the process is isothermal that means at constant temperature.
T = constant
= 0
So, at constant temperature the internal energy and enthalpy is equal to zero. That means,
and 
Answer:
20.11% of oxygen
Explanation:
The reaction is:
2CuO ⇒ 2Cu + O2
If you have an initial amoung of a sample, thi may be have impurities, so you have to start from products to know what you had at the begining.
to make a relation between reagents and products you need to change the mass to mol, then you can relate them with the molar ratio.
Now you have the initial amount of oxygen, to convert to percent you must divide the mass of oxygen between the mass of the sample and multiply by 100

Hello,
Work is done when a force causes an object to move in the same direction that the force is applied..... Friction reduces efficiency because when two surfaces slide past each other, friction resists their motion, and in real machines, some input work is always used to overcome friction.
Hope this helps!!!! Happy Holidays!!!! (:
Solubility product constants are values to describe the saturation of ionic compounds with low solubility. A saturated solution is when there is a dynamic equilibrium between the solute dissolved, the dissociated ions, the undissolved and the compound. It is calculated from the product of the ion concentration in the solution. For barium chromate, the dissociation would be as follows:
BaCrO4 = Ba^2+ + (CrO4)^2-
So, the expression for the solubility product would be:
Ksp = [Ba^2+] [(CrO4)^2-]
we let x = [BaCrO4] = [Ba2+] = [(CrO4)2-] = 2.81x10^-3 g/L ( 1 mol / 253.35 g ) = 1.11x10^-5
Ksp = x(x)
Ksp= x^2
Ksp = (1.11x10^-5)^2
Ksp = 1.23x10^-10
The Ksp of Barium chromate at that same temperature for the solubility would be 1.23x10^-10.