I got you
The molecular formula for the combustion of butane in oxygen is:
2 C4H10 + 13 O2 ---> 8 CO2 + 10 H20
<span>You take the mass of carbon dioxide, 56.8g, divide by its molar mass, 44.01g/mol, to produce the moles of carbon dioxide. This is multiplied by the molar ratio of butane/CO2, (2/8) = 1/4, which gives the moles of butane required to produce the carbon dioxide. Multiply the number of moles of butane by its molar mass, 58.12g/mol, to produce the mass of butane. Mass of butane = 18.8g</span>
The given question is incomplete. The complete question is :
Gaseous butane reacts with gaseous oxygen gas to produce gaseous carbon dioxide and gaseous water . If 1.31g of water is produced from the reaction of 4.65g of butane and 10.8g of oxygen gas, calculate the percent yield of water. Be sure your answer has the correct number of significant digits in it.
Answer: 28.0 %
Explanation:
To calculate the moles :


According to stoichiometry :
13 moles of
require 2 moles of butane
Thus 0.34 moles of
will require=
of butane
Thus
is the limiting reagent as it limits the formation of product and butane is the excess reagent.
As 13 moles of
give = 10 moles of 
Thus 0.34 moles of
give =
of 
Mass of 


The percent yield of water is 28.0 %
333,000 Joules is the amount of energy (heat) in joules required to raise the temperature of 5 kg of iron from 50°C to 200°C.
Explanation:
Data given:
mass of iron 5 Kg or 5000
initial temperature = 50 degree centigrade
final temperature = 200 degrees centigrade
change in temperature (Δ T= 200 -50 degrees centigrade)
= 150 °C
cp (specific heat capacity of iron) = 0.444j/gram C
q (heat supplied) = ?
applying the formula,
q=mcΔT
putting the values in the equation:
q = 5000 X 0.444 X150
q = 333,000 Joules of energy.
The heat required 333,000 Joules of energy is required.
<u>Q</u><u>U</u><u>E</u><u>S</u><u>T</u><u>I</u><u>O</u><u>N</u><u> </u><u>:</u>
- highest energy level for lithium
<u>A</u><u>N</u><u>S</u><u>W</u><u>E</u><u>R</u><u> </u><u>:</u>
- There are 2 electrons on the first energy level and 1 electron on the second. Explain that the first energy level can only have 2 electrons so the next electron in lithium is on the next (second) level. Explain that neon has 10 protons and 10 electrons.
The main factor is the size of the moon. which is small compared to the earth, meaning that the moon has less gravity, and more gas is allowed to escape the surface, Which basically means theres no atmosphere.