Answer:
78.9% yield
Explanation:
% Yield = Actual Lab Yield/Theoretical Yield x 100%
= (204.6g)/(256.5g)·100% = 79.8% Yield
the answer is C
It is a chemical change because heat energy is absorbed and the pack gets colder. A change in temperature is a sign that a chemical reaction has taken place; increase in temperature is an exothermic reaction and decrease in temperature is an endothermic reaction. This is an endothermic chemical reaction.
I think the answer would b C
Answer:
the pressure at c = 0.27 atm
Explanation:
Given that:
number of moles (n) = 1.0 moles
Value of gamma in the monoatomic gas (γ) = 5/3
During an isothermal expansion, the volume at b is = 2.5 times the volume at a ; this implies that:

∴ To calculate the pressure at c from a; the process is adiabatic compression; so we apply:

![\frac{P_c}{P_a}=[\frac{V_a}{V_c}]^{(2/3)](https://tex.z-dn.net/?f=%5Cfrac%7BP_c%7D%7BP_a%7D%3D%5B%5Cfrac%7BV_a%7D%7BV_c%7D%5D%5E%7B%282%2F3%29)
![\frac{P_c}{1.0 atm}=[\frac{1}{2.5}]^{(2/3)](https://tex.z-dn.net/?f=%5Cfrac%7BP_c%7D%7B1.0%20atm%7D%3D%5B%5Cfrac%7B1%7D%7B2.5%7D%5D%5E%7B%282%2F3%29)

Thus, the pressure at c = 0.27 atm