Answer:
Ka = 6.02x10⁻⁶
Explanation:
The equilibrium that takes place is:
We <u>calculate [H⁺] from the pH</u>:
- [H⁺] =  
Keep in mind that [H⁺]=[A⁻].
As for [HA], we know the acid is 0.66% dissociated, in other words:
We <u>calculate [HA]</u>:
Finally we <u>calculate the Ka</u>:
- Ka = ![\frac{[9.12x10^{-4}]*[9.12x10^{-4}]}{[0.138]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5B9.12x10%5E%7B-4%7D%5D%2A%5B9.12x10%5E%7B-4%7D%5D%7D%7B%5B0.138%5D%7D) = 6.02x10⁻⁶ = 6.02x10⁻⁶
 
        
             
        
        
        
Answer is: 5,75·10⁻¹.
Kf = 2,3·10⁶ 1/s.
K = 4,0·10⁸ 1/s.
Kr = ?
Kf - <span>forward rate constant.
K - </span><span>equilibrium constant.
Kr - </span><span>reverse rate constant.
</span>Since both Kf and Kr are constants at a given temperature, their ratio is also a constant that
is equal to the equilibrium constant K.<span>
K = Kf/Kr.
Kr = Kf/K = </span>2,3·10⁶ 1/s ÷ 4,0·10⁸ 1/s = 5,75·10⁻¹.
        
             
        
        
        
Answer:
c. To facilitate a reaction of one substrate to form two products without the use of water
Explanation:
A lyase is an enzyme that catalyzes - accelerates the chemical reaction - in which a substrate is broken into two molecules. The reaction does not involve hydrolysis or oxidation, so the water molecule is not included in the chemical reaction. Thus, the enzyme facilitates the reaction in which a molecule (substrate) is decomposed into two molecules with the elimination of chemical bonds. 
 
        
             
        
        
        
First, we shall calculate the total number of moles present in the final solution.
Number of moles in 0.50 m NaCl = molarity * volume = 0.50 * 3.0 = 1.5 moles.
Number of moles in 0.2777m NaCl = molarity * volume = 0.2777 * 9.0 = 0.24993 moles
Total number of moles = 1.5 + 0.24993 = 1.74993 moles
Second, we shall calculate the total volume of the final solution.
Total volume = 3 + 9 = 12 litres.
The molarity = total number of moles / total volume = 1.74993 / 12 = 0.1458 m
        
             
        
        
        
Answer:
D (or E If properly listed to include the active site option)
Explanation:
A. Is true
Enzymes are organically biochemical catalyst and thus they can speed up the rate of chemical reaction in the body
B is true
They are catalysts as said earlier
C is true
They have active sites. An enzyme does not act on all substrates. They have particular group on which they can act. For example, we have carbohydrates enzymes that act on carbohydrates substrate only. This enzymes have no business acting on a protein substrate.
D. Enzymes are proteins 
One of the important characteristics of enzymes is that they are protenious in nature 
E. This is wrong. Enzymes like any over catalyst are not consumed in the course of the biochemical reaction