We calculate it as follows:
Moles CO2 = 0.01849 g / 44 = 0.000420
<span>Mass C = 0.000420 x 12 = 0.00504 g </span>
<span>Moles H = 2 x 0.006232 / 18 = 0.000692 </span>
<span>Mass H = 0.000692 g </span>
<span>Mass O = 0.005982 - ( 0.00504 + 0.000692) = 0.00025 </span>
<span>Moles O = 0.00025 / 16 = 0.0000156 </span>
<span>C 0.000420
H 0.000692
O 0.0000156
</span>
<span>divide each by the smallest value, giving you the chemical formula as:
</span><span>
C27H44O</span>
Answer:
65.4%
Explanation:
The redox reaction is a 1:1:1 reaction because the reagents suffer a double displacement reaction, and the substance that is substituted have the same charge (H+ and Br-), thus, we first need to know which of the reagents is the limiting.
Let's test the 4-nitrobenzaldehyde as the limiting. The mass needed for sodium borohydride (m) is the mass given of 4-nitrobenzaldehyde multiplied by the stoichiometric mass of sodium borohydride divided by the stoichiometric mass of 4-nitrobenzaldehyde. The stoichiometric mass is the number of moles in the stoichiometric representation (1:1:1) multiplied by the molar mass, so:
m = (4.13 * 37.83*1)/(151.12*1)
m = 1.034 g
So, the mass needed of the other reagent is larger than the mass that was given, so, it will be the limiting, and the stoichiometric calculus must be done with it.
The mass of the product that was expected is then:
m = (0.700*153.14*1)/(37.83*1)
m = 2.83 g
The percent yield is the mass that was formed divided by the expected mass, and then multiplied by 100%:
%yield = (1.85/2.83)*100%
%yield = 65.4%
The balanced equation for the above reaction is as follows;
<span>Fe</span>₂<span>O</span>₃<span> + 3 CO --> 2 Fe + 3 CO</span>₂
<span>stoichiometry of CO to Fe is 3:2
molar volume states that 1 mol of any gas occupies a volume of 22.4 L
If 22.4 L contains 1 mol of CO
Then 3.65 L contains - 1/22.4 x 3.65 = 0.16 mol
3 mol of CO forms 2 mol of Fe
Then 0.16 mol of CO forms - 2/3 x 0.16 = 0.1067 mol of Fe
Therefore mass of Fe produced - 0.1067 mol x 55.8 g/mol = 5.95 g</span>
The sum of the percentage abundance of these two isotopes of the new synthetic element should be equal to 100. If we let x be the percent abundance of the second isotope, we have the equation,
62 + x = 100
The value of x from the equation is 38.