Answer: C. ethanol
The enthalpy of combustion is the amount of heat produced when one mole of ethanol undergoes complete combustion at 25 ° C and 1 atmosphere pressure, yielding products also at 25 ° C and 1 atm.
<u>The enthalpy of combustion of the unknown compound is</u>
ΔH = - 320 kJ / 0.25 mol = - 1280 kJ / mol
<u>To choose a probable compound according to this combustion enthalpy, we must evaluate the deviation in relation to the values reported in the literature for the three probable compounds</u> (methane, ethylene and ethanol). The deviation (e%) will be calculated according to the following equation,
e% = ( | ΔHx - ΔH | / ΔHx ) x 100%
where ΔHx is the enthalpy of combustion of the probable compound.
The following table shows the combustion enthalpies of the probable compounds and their deviation in relation to the enthalpy of ΔH = - 1280 kJ / mol
Compound Enthalpy of combustion (kJ/mol) Deviation
Methane - 890.7 43.8%
Ehylene -1411.2 9.3%
Ethanol -1368.6 6.5%
According to the previous table, we can say that the most probable compound is ethanol, since it has the smallest deviation in relation to the experimental enthalpy value of combustion.
Moles of Zn: 26 / 65 = 0.4
Moles of S: 12.8 / 32 = 0.4
Molar ratio of Zn : S = 1 : 1
Empircal formula: ZnS
The answer is C
Answer:
As you move from left to right, the nucleus gains protons. This increases the positive charge of the nucleus and its attractive force on the electrons. At the same time, electrons are added to the atoms as you move from left to right across a period.
Explanation:
Answer: 11.5 moles of carbon
Explanation:
Based on Avogadro's law:
1 mole of any substance has 6.02 x 10^23 atoms
So, 1 mole of carbon = 6.02 x 10^23 atoms
Z moles = 6.93 x 10^24 atoms
To get the value of Z, cross multiply:
(6.93 x 10^24 atoms x 1mole) = (6.02 x 10^23 atoms x Z moles)
6.93 x 10^24 = (6.02 x 10^23 x Z)
Z = (6.93 x 10^24) ➗ (6.02 x 10^23)
Z = 1.15 x 10
Z = 11.5 moles
Thus, there are 11.5 moles of carbon.
