Answer:
The amount of heat that is released is -925.2 cal
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
Sensible heat is the amount of heat that a body can receive or release without affecting its molecular structure, that is, it does not change the state (solid, liquid, gaseous). In other words, sensible heat is the amount of heat that a body absorbs or releases without any changes in its physical state.
The equation that allows to calculate heat exchanges is:
Q = c * m * ΔT
Where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the variation in temperature.
In this case:
- c= 1

- m= 25.7 g
- ΔT= Tfinal - Tinitial= 49 °C - 85 °C= -36 °C
Replacing:
Q= 1
*25.7 g* (-36 C)
Solving:
Q= -925.2 cal
<u><em>The amount of heat that is released is -925.2 cal</em></u>
<u>Answer:</u> The volume of hydrogen gas required for the given amount of ethylene gas is 113 L
<u>Explanation:</u>
At STP:
1 mole of a gas occupies 22.4 L of volume
We are given:
Volume of ethylene = 113 L
For the given chemical equation:

By Stoichiometry of the reaction:
of ethylene reacts with
of hydrogen gas
So, 113 L of ethylene gas will react with =
of hydrogen gas
Hence, the volume of hydrogen gas required for the given amount of ethylene gas is 113 L
Time Period 3 (300 BC to 1400 AD)
The alchemists were in pursuit of 2 ideals. First, alchemy came about from the belief that cheap metals can be transmuted to gold using the legendary substance <em>Philosopher's Stone</em> for the conversion. These views were greatly influenced by Aristotle. Thus, from 300 BC to 1400 AD, alchemists worked to make the conversion of cheap metals to gold a reality. However, it never succeeded.
After this, the second ideal that the alchemists were in pursuit of was the concoction of an elixir of life to enable people to live longer and cure all ailments. This took place in the 1500s up to the end of the 1600s. Just like the pursuit of the first ideal, efforts to succeed in the second one all led to failure.
Oxygen is more ELECTRONEGATIVE than Hydrogen, which means that the electrons in the atom are coaxed more toward the Central Oxygen atom. Because of this, the charge is not evenly distributed among the molecule, causing it to have positive and negative sides. This is what we call a POLAR molecule.