How many grams of CO2 can form by the complete combustion of 3.95 gram ethane
and 2.25 gram oxygen by the following reaction:
{
} 1 point
{
} 2 points
{
} 2 points
{
} 1 point
{
} 1 point
Amount of CO2 formed :
{
0.0703125 mol O2 x
4 𝑚𝑜𝑙 𝑜𝑓 𝐶𝑂2
7 𝑚𝑜𝑙 𝑂2
x
44.01 𝑔 𝐶𝑂2
1 𝑚𝑜𝑙 𝐶𝑂2
= 1.7682 g CO2
} 1 point
= 1.77 g CO2 1 point
-1 for sig fig
How many grams of CO2 can form by the complete combustion of 4.95 gram
ethylene and 3. 25 gram oxygen by the following reaction:
{
} Balancing 1 point
Molar mass 28.052 1 point
{
{
} 2 points
} 2 points
{
} 1 point
{
} Identifying
Amount of CO2 formed :
{
} 1 point
= 5.59 g CO2 1 point
-1 significant figures
A compound was found to be 90.6% Pb and 9.4% oxygen. What is the empirical
formula for the compound.
90.6 g Pb x
9.4 g O x
= 0.437258687 mol Pb/ 0.437258687 = 1 x3= 3
= 0.5875 mol O2/ 0.437258687 =1.35 x 3 = 4.05
The compound is Pb3O4
For a new element, 68.84% is an isotope with mass 280.7 amu, 2.40% is an isotope with
mass 283.5 amu, and 28.76% is an isotope with mass 284.7 amu. Calculate the average
atomic mass of this new element.
Atomic mass = (0. 6884 x 280.7) + (0.024 x 283.5) + (0.2876 x 284.7)
= 281.9176 amu = 281.9 amu
=
9.4 g O x