Applying for a 2nd MS degree - Should I mention my previous MS in the statement of purpose? Graduate application season is about to start and I would like to apply for MS programs within the US. Ideally, I should apply for a PhD since I already have a MS degree in Inorganic Chemistry. However, I've applied to three different PhD programs in the US and Canada this year and have been rejected to all three, I guess the main reason is that I don't have any publications and I am also a foreign student (from Brazil); hence I decided to try a 2nd MS degree to strengthen my CV and increase the chance of being accepted to a PhD program later.

The question is: should I mention in my application this previous MS in Inorganic Chemistry or should I proceed as if it was going to be my first graduate experience?
There are four different scenarios I can think of:

-I mention the MS in my application and it will be considered a plus, increasing my chance of receiving an assistantship.

-I mention the MS in my application and it will be considered a plus by the admission committee, but they won't be able grant me funding (as teaching or research assistantship) since this will not be my 1st MS degree.

-I mention the MS, but the admission committee thinks it is inappropriate to accept me as a master's student since I already have a degree and I would be rejected.

-I don't mention, I won't have the extra experience on my application but my chances of receiving funding are bigger in case I get accepted into the program.

Do my reasoning seems logical? Apparently there are no restrictions about a 2nd degree anywhere I've searched within the departamental websites of which programs I intend to apply, but I'm still not sure how they would ponder this situation.
There are several factors you should consider: 

1) check if you are obliged to inform the university about all your previous degrees (this mainly depends on the policy of the university). For example, I know that in some European countries it is highly important to declare it due to financial issues, where students with similar degrees cannot get funding support. In some African and Asian countries, it is not allowed at all to join a program with similar degree due to insufficient pedagogical seats. For this be careful not making a false declaration. 

2) in case you are not obliged to declare such an information (Note that it does not mean lying about it), it is better to check if you can make it as a positive point. This should be mentioned in your motivation letter, by intuitively indicating your motivation for the applied program and how its combination with your previous MS will help you to solve difficult problems in the labour market or doing PhD. 

If you cannot find such a connection between the two programs and you find that the motivation is not sufficiently convincing, you can hide your degree as long as you are not obliged or asked to declare it. 

Overall, everything will be based on how you illustrate your motivation.