Note down the formula below
![\boxed{\sf Mass\%\;of\; element=\dfrac{Mass\:of\:the\: element}{Mass\;of\:the\: compound}\times 100}](https://tex.z-dn.net/?f=%5Cboxed%7B%5Csf%20Mass%5C%25%5C%3Bof%5C%3B%20element%3D%5Cdfrac%7BMass%5C%3Aof%5C%3Athe%5C%3A%20element%7D%7BMass%5C%3Bof%5C%3Athe%5C%3A%20compound%7D%5Ctimes%20100%7D)
Mass of the compound
![\\ \sf\longmapsto 15+120=135g](https://tex.z-dn.net/?f=%5C%5C%20%5Csf%5Clongmapsto%2015%2B120%3D135g)
Mass % of Hydrogen:-
![\\ \sf\longmapsto \dfrac{15}{135}\times 100](https://tex.z-dn.net/?f=%5C%5C%20%5Csf%5Clongmapsto%20%5Cdfrac%7B15%7D%7B135%7D%5Ctimes%20100)
![\\ \sf\longmapsto \dfrac{1}{9}\times 100](https://tex.z-dn.net/?f=%5C%5C%20%5Csf%5Clongmapsto%20%5Cdfrac%7B1%7D%7B9%7D%5Ctimes%20100)
![\\ \sf\longmapsto 11.1\%](https://tex.z-dn.net/?f=%5C%5C%20%5Csf%5Clongmapsto%2011.1%5C%25)
Mass % of Oxygen:-
![\\ \sf\longmapsto \dfrac{120}{135}\times 100](https://tex.z-dn.net/?f=%5C%5C%20%5Csf%5Clongmapsto%20%5Cdfrac%7B120%7D%7B135%7D%5Ctimes%20100)
![\\ \sf\longmapsto \dfrac{8}{9}\times 100](https://tex.z-dn.net/?f=%5C%5C%20%5Csf%5Clongmapsto%20%5Cdfrac%7B8%7D%7B9%7D%5Ctimes%20100)
![\\ \sf\longmapsto 88.9\%](https://tex.z-dn.net/?f=%5C%5C%20%5Csf%5Clongmapsto%2088.9%5C%25)
<span>a) molecular, phosphorous pentafluoride
b) ionic, sodium iodide
c) molecular, sulfur dichloride
d) ionic, calcium nitrate
e) ionic, iron(III) chloride
f) ionic?, lanthanum phosphate
g) ionic, cobalt(II) carbonate
h) molecular, dinitrogen tetraoxide
hope this helps!</span><span>
</span>
0.250 mol H2 or 0.5 grams H2. Convert your grams to moles (Na 11.2g = 0.5mol | 9g H2O = .5mol) then use your mole ratio (Na / H2 = 2/1 | H2O 2/1) as a proportion to calculate the # of moles produced from each reactant ( 2/1 = .5/x [solve for x]) and then convert your moles (0.25mol H2) to grams using the molar mass of H2 (H[1]x2 = 2) using multiplication. (moles x molar mass) (.250 x 2) to get your answer of 0.5 grams H2
0 degrees Celsius and 1 atmosphere.