Use of the Data Booklet is relevant to this question.
Anhydrous magnesium nitrate, Mg(NO3)2 , will decompose when heated, giving a white solid and
a mixture of two gases X and Y.
Y is oxygen.
What is the ratio of
released of X mass/
released of y released ?

Question

Use of the Data Booklet is relevant to this question.
Anhydrous magnesium nitrate, Mg(NO3)2 , will decompose when heated, giving a white solid and 
a mixture of two gases X and Y. 
Y is oxygen. 
What is the ratio of 
released of X mass/
released of y released ?

aaronq · Answer

$\sf 2 ~Mg(NO_3)_2+\Delta → 2~ MgO + 4 ~NO_2 + ~O_2$ the ratio is based on their stoichiometric coefficients. http://en.wikipedia.org/wiki/Magnesium_nitrate

anonymous · Answer

why is the answer 1/0.174 ?

aaronq · Answer

Did you have other values. the ratio should be $\sf \dfrac{4}{1}$

aaronq · Answer

oh wait sorry, it says masses. 

Use their molar masses

aaronq · Answer

$\sf \dfrac{184}{32}=\dfrac{1}{0.17391304}$

anonymous · Answer

thank you :)

aaronq · Answer

no problem !