<span>83.9%
First, determine the molar masses of Al(C6H5)3 and C6H6. Start by looking up the atomic weights of the involved elements.
Atomic weight aluminum = 26.981539
Atomic weight carbon = 12.0107
Atomic weight hydrogen = 1.00794
Molar mass Al(C6H5)3 = 26.981539 + 18 * 12.0107 + 15 * 1.00794 = 258.293239 g/mol
Molar mass C6H6 = 6 * 12.0107 + 6 * 1.00794 = 78.11184 g/mol
Now determine how many moles of C6H6 was produced
Moles C6H6 = 0.951 g / 78.11184 g/mol = 0.012174851 mol
Looking at the balanced equation, it indicates that 1 mole of Al(C6H5)3 is required for every 3 moles of C6H6 produced. So given the number of moles of C6H6 you have, determine the number of moles of Al(C6H5)3 that was required.
0.012174851 mol / 3 = 0.004058284 mol
Then multiply by the molar mass to get the number of grams that was originally present.
0.004058284 mol * 258.293239 g/mol = 1.048227218 g
Finally, the weight percent is simply the mass of the reactant divided by the total mass of the sample. So
1.048227218 g / 1.25 g = 0.838581775 = 83.8581775%
And of course, round to 3 significant digits, giving 83.9%</span>
Answer:
-4
Explanation:
In 0.0034 the zeros are preceding numberd and after the decimal point.
Answer:
+2.5
Explanation:
So the oxidation number of S in Na2S4O6is +2.5.
All the elements you listed share a common trait: they are synthetic, radioactive elements. These elements do not have a stable isotope, so for a radioactive element, its most stable isotope's atomic mass will be listed in parentheses.
One such example would be plutonium. This element has 6 different isotopes with differing half-lives. The most stable isotope for plutonium is plutonium-244, with a half-life of around 80 million years. Therefore, the atomic mass listed for plutonium will be (244).
