Answer:
<h2>Translate your language to English </h2>
Critical Thinking Questions
1. Why do you think forensic scientists are so careful that the tests they do are sensitive, reproducible, and specific? What might happen if they were less careful about this?
They have to be careful to ensure as much accuracy as possible.
2.Which type of evidence do you think is most useful in an investigation? Why?
Physical evidence would probably be most important because it is the best way to connect someone directly with that crime.
3.Why do you think that forensic scientists continue to look for class characteristics given their limitations?
Class characteristics are good in court because it provides details of different aspects of the crime.
Answer:
Kb = 
Explanation:
For a weak organic base, the formula to find 
is given by:
where c is the concentration of base.
Here c= 
Substituting the above values in the formula,we get:
Hence:
Kb =
Number 1.c
number 2.a
number 3.b
number 4.d
Answer:
4.77 is the pH of the given buffer .
Explanation:
To calculate the pH of acidic buffer, we use the equation given by Henderson Hasselbalch:
![pH=pK_a+\log(\frac{[salt]}{[acid]})](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%28%5Cfrac%7B%5Bsalt%5D%7D%7B%5Bacid%5D%7D%29)
![pH=-\log[K_a]+\log(\frac{[salt]}{[acid]})](https://tex.z-dn.net/?f=pH%3D-%5Clog%5BK_a%5D%2B%5Clog%28%5Cfrac%7B%5Bsalt%5D%7D%7B%5Bacid%5D%7D%29)
![pH=-\log[K_a]+\log(\frac{[CH_3CH_2COONa]}{[CH_3CH_2COOH]})](https://tex.z-dn.net/?f=pH%3D-%5Clog%5BK_a%5D%2B%5Clog%28%5Cfrac%7B%5BCH_3CH_2COONa%5D%7D%7B%5BCH_3CH_2COOH%5D%7D%29)
We are given:
= Dissociation constant of propanoic acid = 
![[CH_3CH_2COONa]=0.254 M](https://tex.z-dn.net/?f=%5BCH_3CH_2COONa%5D%3D0.254%20M)
![[CH_3CH_2COOH]=0.329 M](https://tex.z-dn.net/?f=%5BCH_3CH_2COOH%5D%3D0.329%20M)
pH = ?
Putting values in above equation, we get:
![pH=-\log[1.3\times 10^{-5}]+\log(\frac{[0.254 M]}{[0.329]})](https://tex.z-dn.net/?f=pH%3D-%5Clog%5B1.3%5Ctimes%2010%5E%7B-5%7D%5D%2B%5Clog%28%5Cfrac%7B%5B0.254%20M%5D%7D%7B%5B0.329%5D%7D%29)
pH = 4.77
4.77 is the pH of the given buffer .
