It should be Quaternary (D)
Answer : The enthalpy change for the decomposition of calcium carbonate is, 178.1 kJ/mol
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. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The given main reaction is,
The intermediate balanced chemical reaction will be,
(1) 
(2) 
(3) 
(4) 
Now we are reversing reaction 1 and then adding reaction 1 and 2, we get :
(1)
(2) 
The expression for enthalpy of change will be,
Thus, the enthalpy change for the decomposition of calcium carbonate is, 178.1 kJ/mol
<span>Answer: 0.00649M
The question is incomplete,
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<span>You are told that the first ionization of the sulfuric acid is complete and the second ionization of the sulfuric acid has a constant Ka₂ = 0.012
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With that you can solve the question following these steps"
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<span>1) First ionization:
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<span>
H₂SO₄(aq) --> H⁺ (aq) + HSO₄⁻ (aq)
Under the fully ionization assumption the concentration of HSO4- is the same of the acid = 0.01 M
2) Second ionization
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<span>HSO₄⁻ (aq) ⇄ H⁺ + SO₄²⁻ with a Ka₂ = 0.012
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<span>Do the mass balance:
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<span><span> HSO₄⁻ (aq) H⁺ SO₄²⁻</span>
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<span /><span /><span> 0.01 M - x x x
</span><span>Ka₂ = [H⁺] [SO₄²⁻] / [HSO₄⁻]</span>
<span /><span>
=> Ka₂ = (x²) / (0.01 - x) = 0.012
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<span>3) Solve the equation:
</span><span>x² = 0.012(0.01 - x) = 0.00012 - 0.012x</span>
<span /><span>
x² + 0.012x - 0.0012 = 0
</span><span />
<span>Using the quadratic formula: x = 0.00649
</span><span />
<span>So, the requested concentratioN is [SO₄²⁻] = 0.00649M</span>
30 electrons = atomic number
Look at your periodic table. You will see zinc has a atomic number (the top number) of 30.
When you add 30 and 35 you get 65. The is the atoms ATOMIC MASS. So looking at zinc on the periodic table, look at its bottom number, which is its atomic mass. It will be 65.
This means the name of the element is ZINC.
Hope this helped!
