Answer:
16.93%.
Explanation:
- If we have 1.0 mol of Fe₃Al₂(SiO₄)₃:
∴ The mass of 1.0 mol of Fe₃Al₂(SiO₄)₃ = (no. of moles of Fe₃Al₂(SiO₄)₃)(the molecular mass of Fe₃Al₂(SiO₄)₃)
∴ The mass of 1.0 mol of Fe₃Al₂(SiO₄)₃ = (1)(the molecular mass of Fe₃Al₂(SiO₄)₃) = (the molecular mass of Fe₃Al₂(SiO₄)₃).
∴ The mass of 1.0 mol of Fe₃Al₂(SiO₄)₃ = 3(atomic weight of Fe) + 2(atomic weight of Al) + 3(molecular weight of (SiO₄)₃) = 497.7474 g.
The mass of Si in 1.0 mole of Fe₃Al₂(SiO₄)₃ = 3(atomic mass of Si) = 3(28.0855 g/mol) = 84.2565 g.
∵ The mass % of Si = (the mass of Si)/(the mass of Fe₃Al₂(SiO₄)₃) = (84.2565 g)/(497.7474 g) = 16.93%.
Molar mass:
O2 = 31.99 g/mol
C8H18 = 144.22 g/mol
<span>2 C8H18(g) + 25 O2(g) = 16 CO2(g) + 18 H2O(g)
2 x 144.22 g --------------- 25 x 31.99 g
10.0 g ----------------------?? ( mass of O2)
10.0 x 25 x 31.99 / 2 x 144.22 =
7997.5 / 288.44 => 27.72 g of O2
hope this helps!
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Cytosine (C) and Guanine (G) are more steady under expanding heat since C and G have three hydrogen bonds while Adenine (An) and Thymine (T) have just two. The more hydrogen bonds there are, the more steady the nucleotides are. More bond dependability requires more warmth vitality to separate the securities, and since G≡C have more hydrogen securities than A=T, they are thusly more steady under expanding heat.
B, radon is correct. Interestingly, it often collects in basements from radioactive decay of rocks such as granite that contain uranium. Because it is an unreactive noble gas and because it is denser than air it sits in basements and must be pumped out. It collects in human lungs and is the second leading cause of lung cancer behind smoking.
