logo

Ask Questions, Get Answers

 
X
 Search
Want to ask us a question? Click here
Browse Questions
Ad
Home  >>  JEEMAIN and AIPMT  >>  Chemistry  >>  Polymers
0 votes

Which one of the following is the formula of weight average molecular mass$(\bar{M_w})$:-

$\begin{array}{1 1}(a)\;\large\frac{\sum m_iM_i}{\sum M_i}&(b)\; \large\frac{\sum m_iM_i}{\sum N_i}\\(c)\;\large\frac{\sum N_iM_i^2}{\sum N_iM_i}&(d)\;\large\frac{\sum N_iM_i}{\sum N_i}\end{array}$

Can you answer this question?
 
 

1 Answer

0 votes
If $m_1,m_2,m_3,.......$ are the masses of species with molecular masses $M_1,M_2,M_3.......$ respectively,then the weight average molecular mass is :
$\bar{M_w}=\large\frac{\sum m_iM_i}{m_i}$
$\Rightarrow \large\frac{\sum N_iM_i^2}{\sum N_iM_i}$
Hence (c) is the correct answer.
answered Mar 12, 2014 by sreemathi.v
 
Ask Question
student study plans
x
JEE MAIN, CBSE, NEET Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App
...