A chemist makes up a solution by dissolving 39.0 g of Mg(NO3)2 in enough water to produce a final solution volume of 257 mL. To calculate the molarity of the solution, what additional information is needed

Explanation:

Hello.

In this case, since the molarity of a solution is computed as the moles of solute over volume of solution:

Since the volume of the solution is 257 mL or also 0.257 L, we compute the moles of solute, which is magnesium nitrate (molar mass = 148.3 g/mol), as shown below:

Thus, the required molarity turns out:

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the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.