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: I am pretty sure it is E
Explanation:
They are all <u>non-metal elements</u>.
Answer:
The amount of CaCl2 produced depends on the amount of HCl in the reaction.
Explanation:
The amount of HCl is used completelyin the reaction unlike CaCO3 which remains after reaction.
Answer:
The periodic table has gone through many changes since Dmitri Mendeleev drew up its original design in 1869, yet both the first table and the modern periodic table are important for the same reason: The periodic table organizes elements according to similar properties so you can tell the characteristics of an element just by looking at its location on the table
Explanation:
hope it helps you
