The given question is incomplete. the complete question is:
The world burns the fossil fuel equivalent of approximately 
kg of petroleum per year. Assume that all of this petroleum is in the form of octane. Calculate how much CO2 in kilograms is produced by world fossil fuel combustion per year.( Hint: Begin by writing a balanced equation for the combustion of octane.)
Answer: 
Explanation:
Combustion is a chemical reaction in which hydrocarbons are burnt in the presence of oxygen to give carbon dioxide and water.
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
To calculate the moles :
According to stoichiometry :
As 2 moles of octane give = 16 moles of 
Thus 
of octane give =
of
Mass of 
Thus of is produced by world fossil fuel combustion per year.
Answer:
As you used two diferent instruments, one is more sensitive than the other.
Explanation:
The sensitivity of an instrument is the minimum amount of magnitude that can be differentiate a measurement system.
In method A, you got 27 cm, so if in method B, you got 27.00, method B is more sensitive. It's like saying that one system measures more than the other
Answer:
v = 16.49 m/s
Explanation:
Given that,
Length of the string, l = 1.15 m
The ball makes 137 complete turns each minute.
We know that, 1 turn = 6.28 rad
137 turns = 860.79 rad
1 min = 60 s
We need to find the tangential velocity of the ball. It can be given by
So, the tangential velocity of the ball is 16.49 m/s.
Answer:
All of the above
Explanation:
All of this is in the solar system.
You got the answer correct. If you would double check
given:C (12 g/mol) H (1 g/mol).
12(8) + 1(8) = 104 g/mol
and for C2H4
12(2)+1(4) = 28g/mol
Also, chemical formula of styrene is<span> C6H5CH=CH2.</span>
