Most of the time, fossils are only partially uncovered on site. They are removed individually or in blocks and often protected by plaster jackets before being taken back ...
Answer: The amount of water produced is 9.3 grams
Explanation:
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.

mass of reactants = mass of methane + mass of oxygen = 22.5 g + 35.7 g = 58.2 g
mass of products = mass of carbon dioxide + mass of water = 48.9 g + mass of water
48.9 g + mass of water = 58.2 g
mass of water = 9.3 g
Answer: - 436.5 kJ.
Explanation:
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation.
The given chemical reaction is,

Now we have to determine the value of
for the following reaction i.e,

According to the Hess’s law, if we divide the reaction by half then the
will also get halved and on reversing the reaction , the sign of enthlapy changes.
So, the value
for the reaction will be:


Hence, the value of
for the reaction is -436.5 kJ.