A 2.35-g sample of an acid, H2X, requires 45.0 mL of a 0.500 M NaOH solution for complete reaction (removing both protons). The molar mass of the acid is: (Ignore significant figures for this problem.)

The molar mass of is 208.88 g/mol

Explanation:

To calculate the number of moles for given molarity, we use the equation:

Molarity of NaOH solution = 0.500 M

Volume of solution = 45.0 mL = 0.045 L     (Conversion factor:  1 L = 1000 mL)

Putting values in above equation, we get:

The chemical equation for the reaction of NaOH and follows:

By Stoichiometry of the reaction:

2 moles of NaOH reacts with 1 mole of

So, 0.0225 moles of NaOH will react with = of

To calculate the number of moles, we use the equation:

Given mass of = 2.35 g

Moles of = 0.01125 moles

Putting values in above equation, we get:

Hence, the molar mass of is 208.88 g/mol

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.