Solution:
Given:
Calcium and Oxygen ions each having valence = 2 or 2 valence electrons
seperation distance, r = 1.25nm = 
m
Coulombian force for two point charges seperated by a distance 'r' is given by:
F = 
(1)
Now, we know that
q = ne
where, n = no. of electrons
e = charge of an electron = 
C
= 
e = 2e
= 
e = 2e
Using Eqn (1)
F = 
F = 
N
Since, the force is between two opposite charged ions, it is attractive in nature.
Answer:
X=0.194
T=-33.6C
Explanation:
Hello!
To solve this problem use the following steps!
1. We will call the expansion valve inlet 1 and exit 2
2.Through laboratory tests, thermodynamic tables were developed, these allow to know all the thermodynamic properties of a substance (entropy, enthalpy, pressure, specific volume, internal energy etc ..)
through prior knowledge of two other properties such as pressure and temperature.
3. Find the enthalpy of state 1 using pressure and temperature using thermodynamic tables
h1=Enthalpy(Ammonia;T=24C;P=1000kPa)=312.9KJ/kg
4. An expansion valve is a device which does not have heat or work exchange which means that the enthalpy of state one is equal to that of state 2, so using thermodynamic tables uses the pressure of state 2 and enthalpy of state 1 to find quality and temperature
x2=Quality(Ammonia;P=100kPa;h=h1=312.9KJ/kg)
=0.194
T2=Temperature(Ammonia;P=100kPa;h=h1=312.9KJ/kg)=-33.6C
In surface mining, stripping ratio or strip ratio refers to the amount of waste (or overburden) that must be removed to release a given ore quantity.
