Isobaric transition, first law: <span>H=ΔU+w</span>
for a gas expansion: <span>w=<span>P<span>ext</span></span>∗ΔV</span>
to convert to joules, you need the gas constants.
R = 0.08206 L atm/mol*K, R=8.314 J/mol*K
<span>w=<span>P<span>ext</span></span>∗ΔV∗<span><span>8.314 J/mol∗K</span><span>0.08206 L atm/mol∗K</span></span></span>
<span>ΔU=ΔH−[<span>P<span>ext</span></span>∗ΔV∗<span><span>8.314 J/mol∗K</span><span>0.08206 L atm/mol∗K</span></span>]</span>
<span>ΔU=−75000 J−[(43.0atm)∗(2−5)L∗<span><span>8.314 J</span><span>0.08206 L atm</span></span>]</span>
Then you need to convert to kJ.
by the way U=E, internal energy.
Number of moles of FeCl2 used = mass/ molar mass
Number of moles = 507/126.751 = 4.
If one mole of Fe reacts with two moles of sodium
Then 4 moles of Fe produces 8 moles of sodium.
Number of moles of sodium = mass/molar mass
Molar mass of sodium chloride = 23 +35.5 = 58.5 g/mol
Hence mass = 8 * 58.5 = 468 g. Hence Option A.
The balanced net reactiion for the following half cells will be
Sn + Cr²⁺ ---> Sn²⁺ + Cr
<h3>What are
Half cells ?</h3>
A half cell is one of the two electrodes of an electrochemical cell.
An electrochemical cell comprises two half cells, where every half cell contains an electrode and an electrolyte.
A salt bridge or direct contact is needed to connect two half cells.
The balanced net reactiion for the given half cells will be
Sn + Cr²⁺ ---> Sn²⁺ + Cr
Learn more about Half cell here ;
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Answer: Option (b) is the correct answer.
Explanation:
State of a substance changes when heat is provided to a substance.
This is because when we heat water then intermoleclar forces present within its molecules tend to break down. Due to this molecules start to move away from each other.
As a result, kinetic energy of molecules increases and they collide rapidly. Hence, solid state of water changes into liquid state and upon excessive heating liquid state of water changes into vapor state.
Thus, we conclude that temperature of water needs to change in order to change its state of matter.