Answer : The value of for the reaction is +571.6 kJ/mole.
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 chemical reaction is,
Now we have to determine the value of for the following reaction i.e,
According to the Hess’s law, if we reverse the reaction then the sign of change.
So, the value for the reaction will be:
Hence, the value of for the reaction is +571.6 kJ/mole.
Answer:
Kindly check the attached picture for the diagram showing the titration curve.
Explanation:
The term "titration" is an important part of chemistry because it is being used in the Determination of the concentration is the unknown.
In this question, the titration is done between a polyprotic weak acid, that is Phosphoric acid (H3PO4) and a strong base, NaOH.
H3PO4 + OH^- -----------------> H2O + H2PO4^-.
H2PO4^-2 + OH^- ---------------> H2O + HPO4^2-
HPO4^- + OH^- ------------------> H2O + PO4^3-.
Answer:
mass (g) needed = 710.2 grams Na₂SO₄(s)
Explanation:
Needed is 2.5 Liters of 2.0M Na₂SO₄; formula wt Na₂SO₄ = 142.04g/mol.
mass (grams) of Na₂SO₄(s) = Molarity needed x Volume needed in Liters x Formula Wt of solute
mass (grams) of Na₂SO₄(s) = (2.5L)(2.0M)(142.04g/mol) = 710.2 grams Na₂SO₄(s)
Mixing: Transfer 710.4 grams Na₂SO₄ into mixing vessel and add water-solvent up to but not to exceed 2.5 Liters total volume. Mix until dissolved.
Gives 2.5 Liters of 2.0M Na₂SO₄(aq) solution.