Molal or molar? There is a difference
Answer:
A
Explanation:
Same air has special carakteristik features
Answer:
The weight-average molar mass of polystyrene is 134,160 g/mol.
Explanation:
Molar mass of the monomer styrene ,
, M=104 g/mol
Given , number average molar mass of the polymer , M'= 89,440 g/mol
Degree of polymerization = n
![n=\frac{M'}{M}=\frac{89,440 g/mol}{104 g/mol}=860](https://tex.z-dn.net/?f=n%3D%5Cfrac%7BM%27%7D%7BM%7D%3D%5Cfrac%7B89%2C440%20g%2Fmol%7D%7B104%20g%2Fmol%7D%3D860)
The weight-average molar mass = ![M_{avg}=?](https://tex.z-dn.net/?f=M_%7Bavg%7D%3D%3F)
Molar mass dispersity is ratio of weight-average molar mass to the number average molar mass of the polymer.
![\text{Molar mass dispersity}=\frac{M_{avg}}{M'}](https://tex.z-dn.net/?f=%5Ctext%7BMolar%20mass%20dispersity%7D%3D%5Cfrac%7BM_%7Bavg%7D%7D%7BM%27%7D)
![1.5=\frac{M_{avg}}{89,440 g/mol}](https://tex.z-dn.net/?f=1.5%3D%5Cfrac%7BM_%7Bavg%7D%7D%7B89%2C440%20g%2Fmol%7D)
![M_{avg}=89,440 g/mol\times 1.5 = 134,160 g/mol](https://tex.z-dn.net/?f=M_%7Bavg%7D%3D89%2C440%20g%2Fmol%5Ctimes%201.5%20%3D%20134%2C160%20g%2Fmol)
The weight-average molar mass of polystyrene is 134,160 g/mol.
Answer:“If we’ve covered all of the potential sources, and we know the unique signature of the sand from these different sources, and we find it on a beach somewhere, then we basically know where it came from,” explained Barnard.
Explanation:
<span>An exothermic reaction is one in which there is the production of heat whereas an endothermic reaction is one in which heat is absorbed. For the choices above, the answer would be letter B. Ice melting in water and an ice pack turning cold absorbs heat which is why it is an endothermic reaction. Exploding fireworks and gasoline burning gives off heat which is why it is an exothermic reaction.</span>