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.
Paramecia are examples of unicellular organisms. They are protists.
<h3>Protists</h3>
Protists are eukaryotic unicellular (single-celled) organisms that do not fit into any other category.
Paramecia are protists microorganisms generally found in aquatic habitats (e.g., a pond).
Paramecia generally have an oblong shape and they are covered with tiny structures known as cilia (for motion).
Learn more about protists here:
brainly.com/question/12206236
Answer:
<h2>225 g</h2>
Explanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volume
From the question we have
mass = 0.9 × 250
We have the final answer as
<h3>225 g</h3>
Hope this helps you
Answer:
what is in your chemistry home work I can try for...