Hello there what is the question?
The strong Base with a pH of 12 is reduced by 4 units upon being added with solution Y. If you added a strong acid to the strong base, all ions are present in the solution, yes? So every OH- is neutralised by every H+ for example, meaning the resultant pH should be 7. The resultant pH is only 8 however, so solution Y must be a <em>weak acid </em>only!
Enthalpy is a state function
Explanation:
The Hess's law allows us to determine the enthalpy change of a reaction because enthalpy is a state function. It does not depend on the individual path take in going from reactants to products in the reaction.
- Enthalpy changes are the heat changes accompanying physical and chemical changes.
- It is the difference between the heat content of product in the final state and the reactants.
- Enthalpy changes for some reactions are not easily measurable experimentally.
- To calculate such heat changes, we apply the Hess's law of heat summation.
- The law states that "the heat change of a reaction is the same whether it occurs in a step or several steps".
- The Hess's law is simply based on the first law of thermodynamics by which we know that energy is conserved in every system.
learn more:
Hess's law brainly.com/question/11293201
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I think you divide something
Answer:
55.75g
Explanation:
From
m/M = CV
Where
m= required mass of solute
M= molar mass of solute
C= concentration of solution
V= volume of solution=675ml
Molar mass of solute= 3(23) + 31 + 4(16)= 69+31+64=164gmol-1
Number of moles of sodium ions present= 1.5× 675/1000= 1.01 moles
Since 1 mole of Na3PO4 contains 3 moles of Na+
It implies that 1.01/3 moles of Na3PO4 are present in solution= 0.34moles
mass of Na3PO4= number of moles × molar mass= 0.34 × 164 =55.75g
