I think this is how you do it:
 
        
             
        
        
        
Answer:
pH solutions cause the water to become more basic or more acidic therefore would force the organisms to adapt to their new situations
 
        
             
        
        
        
1.  False, the water being stored behind the dam has potential energy until it begins to flow through the dam (it is then converted to kinetic energy).    
2.  True
3.  True
Hope this helped! :)  
        
             
        
        
        
Answer:
0.3023 M
Explanation:
Let Picric acid = 
So,  
     +       
          ⇄      
     +     
The ICE table can be given as:
                           
     +       
          ⇄      
     +     
Initial:                0.52                                               0                  0
Change:             - x                                                 + x                 + x
Equilibrium:       0.52 - x                                        + x                 + x
Given that; 
 acid dissociation constant  (
) = 0.42
![K_a = \frac{[H_3O^+][Picric^-]}{H_{picric}}](https://tex.z-dn.net/?f=K_a%20%3D%20%5Cfrac%7B%5BH_3O%5E%2B%5D%5BPicric%5E-%5D%7D%7BH_%7Bpicric%7D%7D)
![0.42 = \frac{[x][x]}{0.52-x}}](https://tex.z-dn.net/?f=0.42%20%3D%20%5Cfrac%7B%5Bx%5D%5Bx%5D%7D%7B0.52-x%7D%7D)
![0.42 = \frac{[x]^2}{0.52-x}}](https://tex.z-dn.net/?f=0.42%20%3D%20%5Cfrac%7B%5Bx%5D%5E2%7D%7B0.52-x%7D%7D)
0.42(0.52-x) = x²
0.2184 - 0.42x = x²
x²  + 0.42x - 0.2184 = 0                   -------------------- (quadratic equation)
Using the quadratic formula;
    ;     ( where +/-  represent ± )
= 
= 
= 
     OR   
= 
       OR    
= 
                 OR    
= 0.30225          OR     - 0.72225
So, we go by the +ve integer that says:
x =  0.30225 
x = [ 
 ] = [   
 ] =  0.3023  M
∴  the value of  [H3O+] for an 0.52 M solution of picric acid  = 0.3023 M     (to 4 decimal places).
 
        
             
        
        
        
Answer: 7.79 grams of ethanol were put into the beaker.
Explanation:
To calculate the mass of ethanol, we use the equation:

Density of ethanol = 0.779 g/mL
Volume of water = 10.00 mL
Putting values in above equation, we get:

Thus 7.79 grams of ethanol were put into the beaker.