How many mL of the 3.00 M HCl stock solution is needed to prepare 250.0 mL of a 1.10 M HCl solution?

91.7 mL are needed to prepare the diluted solution

Explanation:

When you dilute a determined solution  the molarity and the volume for both solutions (diluted and concentrated), are the same.

M concentrated . Concentrated volume = M diluted . Diluted volume

3 M . Concentrated volume = 1.10 M . 250 mL

Concentrated volume → ( 1.10 M . 250 mL) /  3M = 91.7 mL

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.