Answer:
2.76 (full answer) 2.7617e-6
Explanation:
 
        
             
        
        
        
Answer:
A. for K>>1 you can say that the reaction is nearly irreversible so the forward direction is favored. (Products formation)
B. When the temperature rises the equilibrium is going to change but to know how is going to change you have to take into account the kind of reaction. For endothermic reactions (the reverse reaction is favored) and for exothermic reactions (the forward reaction is favored)
Explanation:
A. The equilibrium constant K is defined as

In any case  
aA +Bb  equilibrium Cd +dD
where K is:
![K= \frac{[C]^{c}[D]^{d}}{[A]^{a}[B]^{b}}](https://tex.z-dn.net/?f=K%3D%20%5Cfrac%7B%5BC%5D%5E%7Bc%7D%5BD%5D%5E%7Bd%7D%7D%7B%5BA%5D%5E%7Ba%7D%5BB%5D%5E%7Bb%7D%7D)
[] is molar concentration.
If K>>> 1 it means that the molar concentration of products is a lot bigger that the molar concentration of reagents, so the forward reaction is favored.
B. The relation between K and temperature is given by the Van't Hoff equation

Where: H is reaction enthalpy, R is the gas constant and T temperature.  
Clearing the equation for  we get:
 we get:

Here we can study two cases: when delta  is positive (exothermic reactions) and when is negative (endothermic reactions)
 is positive (exothermic reactions) and when is negative (endothermic reactions)
For exothermic reactions when we increase the temperature the denominator in the equation would have a negative exponent so  is greater that
 is greater that  and the forward reaction is favored.
 and the forward reaction is favored. 
When we have an endothermic reaction we will have a positive exponent so  will be less than
 will be less than  the forward reactions is not favored.
 the forward reactions is not favored.  

 
        
             
        
        
        
Chromium has the electron configuration [Ar]4s13d5 and exhibits oxidation numbers 2+, 3+, and 6+. When chromium loses two electrons, it forms the Cr2+ ion and has the configuration [Ar]3d4. 
The Answer is B. [Ar]3d4
 
        
             
        
        
        
Answer:
B) Cu(s) is metal that reacts spontaneously with NiCl2(aq).