Fossil fuels are buried geologic deposits of organic materials. They are made of decaying plants and animals that have been turned into to natural oil. A few examples of fossil fuels are coal and oil.
Answer:
The new pressure is 44.4 kPa.
Explanation:
We have,
Initial volume, 
Initial pressure, 
It is required to find the new pressure when the volume is increased to 50 ml. The relationship between pressure and volume is known as Boyle's law.

is final pressure

So, new pressure is 44.4 kPa.
Since we already have the balanced equation, we know that the ratio between
is
respectively.
So then we can set up a proportion to find the number of moles produced when 2.90 moles of Na react completely:

Then we cross multiply and solve for x:


Therefore, we know that when 2.90 moles of Na react completely, there are 1.45 moles of
that are produced.
Your answer is correct.
MgO(s) + H2O(l) ----> Mg(OH)2(aq)
:-) ;-)
Answer:
The mass was there all along, it was just in the air. The weight of the oxygen from the air is not weighed in the beginning, only at the end as part of the product, making it seem like there is a total mass change.