Answer:
0.161moles
Explanation:
Given parameters:
Mass of Fe = 18g
Oxygen gas is in excess
Unknown:
Number of moles of Fe₂O₃ produced = ?
Solution:
To start with, let us write a chemically balanced equation before proceeding to understand the nuances of this problem.
4Fe + 3O₂ → 2Fe₂O₃
In the equation above above, 4 mole of iron combined with 3 moles of oxygen gas to 2 moles of Fe₂O₃.
In solving this problem, we can identify that Fe is the limiting reactant since we have been told oxygen gas is in excess. The suggests that the extent to which the product is formed and the reaction proceeds hinges on the amount of Fe we have.
It is best to work from the given, or known reactant to the unknown
The known in this scenario is the mass of Fe. Let us find the number of moles of this specie;
Number of moles of Fe = 
Molar mass of Fe = 56g/mol
Number of moles = 
= 0.32mol
Using this known number of moles of Fe, we can relate it to that of the unknown amount of the product and obtain the number of moles.
4 moles of Fe produced 2 moles of Fe₂O₃
0.32 moles of Fe will produce 
= 0.161moles
Answer:
(b) 50 mL = 0.50 L
Explanation:
Metric system is a measurement system that uses decimalized in all their factor, which mean every rank difference can be expressed as a factor of 10(deci=10). The decimalized number makes it easier to convert the unit, make the metric system easier to be learned and used.
The Metric system will use a prefix to determine the factor, a kilo is 1000, mili is 1/1000, centi is 1/100, pico is 1/10^12.
(a) 1 km = 1000 m
True, kilo is 1000
(b) 50 mL = 0.50 L
This option is false. mili is 1/1000, so 50/1000= 0.05 L
(c) 125 mm = 12.5 cm
True, mili is 1/1000 while centi is 1/100.
So 125mm will be: 125mm * 100mm/1000cm= 12.5cm
(d) 23 pm = 0.000 000 000 023 m
True, pico is 10^-12
Yes since for atoms to be of the same element , they must have the same number of protons inside their nucleus . This means that 1- they will all have the same nucleon number ( mass number ) and that 2-they will all have the same number of electrons in their outermost shell which determines the chemical properties of the atom.
Yes you can use that 1 equation.. P1V1/(n1T1) = P2V2/(n2T2) for ALL of your two state ideal gas law type problems. Use it in place of boyles, charles, avogadros, combined, etc laws...just like I showed you above
<span>(1).. write down P1V1/(n1T1) = P2V2/(n2T2) </span>
<span>(2).. rearrange for your desired unknown </span>
<span>(3).. determine what is constant and what varies.. cancel the constants </span>
<span>(4).. plug and chug.. don't forget Temperature must be on an absolute scale.. R or K.. never °F nor °C </span>
No, the distance from the first stop to the schools and the average speed is required.
