Answer:
Explanation:
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In this case, when we want to balance chemical reactions such as in this case, the idea is to equal to number of atoms of each element at each side of the equation according to the lay of conservation of mass, just as shown below:
Because we have four phosphorous and ten oxygen atoms at each side.
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Answer: The correct answer is: " 0.54 g " .
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Explanation:
Note that "hydrogen gas" is:
H₂ (g) ; that is: a "diatomic element" (diatomic gas) ;
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The molecular weight of "H" is: 1.00794 g ;
(From the Periodic Table of Elements).
So, the molecular weight of: H₂ (g) is:
" 1.00794 g * 2 = 2.01588 g ; {use calculator) ;
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Note the conversion for a gas at STP:
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1 mol of a gas = 22.4 L gas;
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i.e. " 1 mol / 22.4 L " ;
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So: " 5.7 L H₂ (g)
The "L" ("literes" cancel out to "1" ; since "L/L = 1 ;
The "mol" (moles) cancel out to "1" ; since "mol/mol = 1 ;
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and we are left with:
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[5.7 * 2.104588 g ] / 22.4 = ? g ;
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→ [ 11.9961516 g ] / 22.4 =
0.53554248214 g ;l
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We round this value to: " 0.54 g " ;
→ since "5.7 L " has 2 (two) significant figures;
22.4 is an exact number conversion;
and "5.7 L" has fewer significant figures than:
" 2.104588 " ; or: " 1.00794 " .
→ as such: We round to "2 (two) significant figures."
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Hope this is helpful. Wishing you the best in your academic endeavors!
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