Answer:
All of the above.
Explanation:
In positive deviation from Raoult's Law occur when the vapour pressure of components is greater than what is expected value in Raoult's law.
When a solution is non ideal then it shows positive or negative deviation.
Let two solutions A and B to form non- ideal solutions.let the vapour pressure of component A is
and vapour pressure of component B is
.
= Vapour pressure of component A in pure form
= Vapour pressure of component B in pure form
=Mole fraction of component A
=Mole fraction of component B
The interaction between A- B is less than the interaction A- A and B-B interaction.Therefore, the escaping tendency of liquid molecules in mixture is greater than the escaping tendency in pure form.Hence, the vapour pressure of a mixture is greater than the initial value of vapour pressure.
,
Therefore, 
Therefore, the enthalpy of mixing is greater than zero and change in volume is greater than zero.
Hence, option a,b,c and d are true.
Question 1
Fe(III) forms a chelate complex with salicylic acid which has purple color. therefore, when a solution is made either with salicylic acid or with aspirin having trae amount of salicylic acid in it, we see color formation in solution due to the resulting complex formed.
Question 2
The Fe(III) itself absorbs some light and gives an absorbance value for the solution. Therefore, it is necessary to blank the spectrophotometer with a Fe(III) solution prior to measurement of test solutions.
Answer:

Explanation:
Complete ionic equation : In complete ionic equation, all the substance that are strong electrolyte and present in an aqueous are represented in the form of ions.
Net ionic equation : In the net ionic equations, we are not include the spectator ions in the equations.
Only the species which are present in aqueous state dissociate.
Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.
(a)
The balanced molecular equation will be,
The complete ionic equation in separated aqueous solution will be,
In this equation the species present are,
are the spectator ions.
Hence, the net ionic equation contains specie is

Answer:
−2399.33 kJ
Explanation:
If NH₄NO₃ reacts with fuel oil to give a ΔH of -7198 for every 3 moles of NH₄NO₃
What is the enthalpy change for 1.0 mole of NH₄NO₃ in this reaction
∴ For every 1 mole, we will have
of the total enthaply of the 3 moles
so, to determine the 1 mole; we have:

= −2399.33 kJ
∴ the enthalpy change for 1.0 mole of NH₄NO₃ in this reaction = −2399.33 kJ