Answer : The pH of a 0.1 M phosphate buffer is, 6.86
Explanation : Given,

Concentration of acid = 0.1 M
Concentration of conjugate base (salt) = 0.1 M
Now we have to calculate the pH of buffer.
Using Henderson Hesselbach equation :
![pH=pK_a+\log \frac{[Salt]}{[Acid]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BSalt%5D%7D%7B%5BAcid%5D%7D)
Now put all the given values in this expression, we get:


Therefore, the pH of a 0.1 M phosphate buffer is, 6.86
 
        
             
        
        
        
Answer:
It's A
Explanation:
Animals get the nitrogen they need by eating plants or other animals that contain nitrogen. When organisms die, their bodies decompose bringing the nitrogen into soil on land or into ocean water. Bacteria alter the nitrogen into a form that plants are able to use.
 
        
             
        
        
        
White gold is considered an alloy of nickel and gold.
Alloy is the term which refers to the combination of metals, in which a new type of a metal is created. When you mix gold and some other white metal (such as nickel, palladium, or manganese), you get an alloy known as white gold. 
        
                    
             
        
        
        
Answer:
 the experimental variable
Explanation: