Answer: The final energy is 1,700 J
Explanation: According to first law of thermodynamics:
=Final energy-initial energy=Change in internal energy
q = heat absorbed or released
w = work done by or on the system
w = work done by the system=
{Work done by the system is negative as the final volume is greater than initial volume}
q = +500J {Heat absorbed by the system is positive}
w = work done by the system = -300J
Cells are the basic building blocks of all living things
<span>
</span>Basic Calcium Facts
Name: Calcium
Atomic Number: 20
Element Symbol: Ca
Group: 2
Period: 4
Block: s
Element Family: Alkaline Earth
Atomic Mass: 40.078(4)
Electron Configuration: [Ar]4s<span>2
</span>
Full: 1s22s22p63s23p64s2 (full)
Answer:
The concentration of chloride ion is 
Explanation:
We know that 1 ppm is equal to 1 mg/L.
So, the 
content 100 ppm suggests the presence of 100 mg of in 1 L of solution.
The molar mass of is equal to the molar mass of Cl atom as the mass of the excess electron in is negligible as compared to the mass of Cl atom.
So, the molar mass of is 35.453 g/mol.
Number of moles = (Mass)/(Molar mass)
Hence, the number of moles (N) of present in 100 mg (0.100 g) of is calculated as shown below:
So, there is 
of present in 1 L of solution.
Answer:
ΔHr = -86.73 kJ/mol
Explanation:
Using Hess's law, you can calculate ΔH of any reaction using ΔH°f of products and reactants involed in the reaction.
<em>Hess law: ∑nΔH°f products - ∑nΔH°f reactants = ΔHr</em>
<em>-Where n are moles of reaction-</em>
For the reaction:
Fe³⁺(aq) + 3 OH⁻(aq) → Fe(OH)₃(s)
Hess law is:
ΔHr = ΔH°f Fe(OH)₃ - ΔH°f Fe³⁺ - 3×ΔH°f OH⁻
Where:
ΔH°f Fe(OH)₃: −824.25 kJ/mol
ΔH°f Fe³⁺: −47.7 kJ/mol
ΔH°f OH⁻: −229.94 kJ/mol
Replacing:
ΔHr = −824.25 kJ/mol - (−47.7 kJ/mol) - (3×-229.94 kJ/mol)
<em>ΔHr = -86.73 kJ/mol</em>
