Answer:
Approximately 39.7 kJ.
Assumptions: the specific heat capacity of water is
, the melting point of water is
, and that the boiling point of water is
.
Explanation:
It takes five steps to convert 13.0 grams of
ice to steam at
.
- Step one: heat the 13.0 gram of ice from
to
. The change in temperature would be
. - Step two: supply the heat of fusion to convert that 13.0 gram of ice to water.
- Step three: heat the 13.0 gram of water from
to
. The change in temperature would be
. - Step four: supply the heat of vaporization to convert that 13.0 gram of water to steam.
- Step five: heat the 13.0 gram of steam from
to
. The change in temperature would be
.
<h3>Energy required for step one, three, and five</h3>
The following equation gives the amount of energy
required to raise the temperature of an object by a
:
.
In this equation,
is the specific heat of this substance,
is the mass of the substance, and
is the change in the temperature of the object.
Assume that there's no mass loss in this whole process. The value of
would stay the same at
.
.
<h3>Energy required for step two and four</h3>
The equations for the energy of fusion and energy of vaporization are quite similar:
.
.
where
is the number of moles of the substance.
Look up the relative atomic mass of oxygen and hydrogen from a modern periodic table:
Hence the molar mass of water:
.
Number of moles of
molecules in
:
.

<h3>Energy required for all five steps, combined</h3>
.
Considering a reaction:
A → B
The rate equation may be described as:
r = -k[A]ⁿ
Taking the natural log,
ln(r) = -nln([A]) + ln(k)
Therefore, the only time the graph of ln[A] vs time will be a straight line is when the order of the reaction is 0, meaning the reaction is independent of reactant concentration.
Answer:
c . a proton
Protons and neutrons have approximately the same mass, about 1.67 × 10−24 grams
The masses of the 2 most
common isotopes of Cl are 35 and 37. Therefore we can formulate 3 possible
masses of Cl2:
<span>
35 + 35 = 70
35 + 37 = 72
37 + 37 = 74
<span>However, Cl 35 is the most common isotope of chlorine of the
two therefore it is the most probable that two Cl 35 atoms will combine, so 70
is the most common among all.
</span></span>