Percentage by mass of elements in MgBr2, Ca(NO3)2, and NH4NO3

[rpatel]

Calculate the percentage by mass of the elements shown in the following compounds

A) Br in MgBr2

b) O in Ca(NO3)2

c) N in NH4NO3


any help is appreichated

thanks

regards

 

[dmoravec]

the percent mass will be equal to [mass of element in compound]/[mass of total compound]*100%. The only thing to watch out for is when a compound has a few atoms of the same element in it. [ie: for the first one you have 2 bromide ions so the answer would be 2*molecular mass of bromide / mass of magnesium (II) bromide * 100%]

 

[rpatel]

thank you.