COLLEGE CHEMISTRY 35 POINTS
Determine the percent yield when 12 g of CO2 are formed experimentally from the reaction of 0.5 moles of C8H18 reacting with excess oxygen according to the following balanced equation:

2 C8H18(l) + 25 O2(g)  16 CO2(g) + 18 H2O(l)

Please show your work.

6.81% is the percent yield when 12 g of CO2 are formed experimentally from the reaction of 0.5 moles of C8H18 reacting with excess oxygen.

Explanation:

Data given:

mass of carbon dioxide formed = 12 grams (actual yield)

atomic mass of CO2 = 44.01 grams/mole

moles of = 0.5

Balanced chemical reaction:

2 + 25 ⇒ 16 C + 18

number of moles of carbon dioxide given is

number of moles =

number of moles=

number of moles of carbon dioxide gas = 0.27 moles

from the reaction 2 moles of reacts to produce 16 moles of C

So, when 0.5 moles reacted it produces x moles

=

x = 4

4 moles of carbon dioxide formed, mass from it will give theoretical yield.

mass  = number of moles x molar mass

mass = 4 x 44.01

        = 176.04 grams

percent yield = x 100

percent yield = x 100

     percent yield  = 6.81 %

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."