D. The coldest regions of outer space
Answer:
In pure water, at 25C, the [H3O+] and [OH-] ion concentrations are 1.0 x 10-7 M. The value of Kw at 25C is therefore 1.0 x 10-14. Although Kw is defined in terms of the dissociation of water, this equilibrium constant expression is equally valid for solutions of acids and bases dissolved in water.
Explanation:
Answer:
C₆H₅COOH Benzoic Acid
Explanation:
Here we are using the extraction method to separate benzoic acid from naphtalene in the ether solution by reacting it with the base sodium bicarbonate to produce the salt sodium benzoate ( naphtalene remains in the organic layer ) .
The sodium benzoate is completely soluble in the aqueous layer being a salt, and reacts with hydrochloric acid ( again an acid base reaction ) which precipitates the benzoic acid since the it is insoluble in water hence separating it.
Answer:
Sulfur
Explanation:
Sulfur is a chemical element that is represented with the chemical symbol "S" and the atomic number 16 on the periodic table.
The given chemical equation is:
On balancing the equation we get,
Calculating enthalpy of formation of this reaction from the standard heats of formation of the products and reactants:
Δ![H_{reaction}^{0}=[H_{f}^{0}(Al_{2}O_{3}(s)) + (3*H_{f}^{0}(H_{2}SO_{4}(aq))] - [H_{f}^{0}(Al_{2}SO_{4}(aq)) + (3*H_{f}^{0}(H_{2}O(l))]](https://tex.z-dn.net/?f=H_%7Breaction%7D%5E%7B0%7D%3C%2Fp%3E%3Cp%3E%3D%5BH_%7Bf%7D%5E%7B0%7D%28Al_%7B2%7DO_%7B3%7D%28s%29%29%20%2B%20%283%2AH_%7Bf%7D%5E%7B0%7D%28H_%7B2%7DSO_%7B4%7D%28aq%29%29%5D%20-%20%20%20%5BH_%7Bf%7D%5E%7B0%7D%28Al_%7B2%7DSO_%7B4%7D%28aq%29%29%20%2B%20%283%2AH_%7Bf%7D%5E%7B0%7D%28H_%7B2%7DO%28l%29%29%5D)
=[(-1669.8kJ/mol)+ {3* (-909.27 kJ/mol)}]-[(-3442kJ/mol)+{3*(-285.8 kJ/mol)}]
=[(-4397.61kJ/mol)]-[(-4299.4kJ/mol)]
=-98.21kJ/mol
Total enthalpy change when 15 mol of 
reacts will be=
