Answer: I & III
Explanation: Solutes are the substances which are minimum in quantity and which is required to dissolve in the solvent (which is larger in quantity) in order to make a solution.
In the asked question, it is given that the water is the solvent and from the given solutes we have to pick which would make an aqueous solution with the highest concentration of solute possible.
Thus the most appropriate answers could be the Ammonia and hexanol which can make the highest possible concentration of solute as ammonia is the gas which is highly soluble in water and hexanol is an alcohol which has an affinity for water. Thus the correct option is I & III
Answer: Water is the solvent in this recipe.
Explanation: A solvent is " a molecule that has the ability to dissolve other molecules". Lemon juice and sugar are solutes.
Answer:

Explanation:
Hello!
In this case, when two substances at different temperature are put in contact and an equilibrium temperature is attained, we can evidence that the heat lost by the hot substance (metal) is gained by the cold substance (water) and we can write:

Which can be also written as:

Thus, since we need the specific heat of the metal, we solve for it as shown below:

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<u>Answer:</u> The correct answer is Option D.
<u>Explanation:</u>
Enthalpy change is defined as the difference in enthalpies of all the product and the reactants each multiplied with their respective number of moles. It is represented as 
The equation used to calculate enthalpy change is of a reaction is:
![\Delta H^o_{rxn}=\sum [n\times \Delta H^o_f_{(product)}]-\sum [n\times \Delta H^o_f_{(reactant)}]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28product%29%7D%5D-%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28reactant%29%7D%5D)
Hence, the correct answer is Option D.