If the titration of 25.0 ml sample of hydrochloric acid (hcl) requires 22.15 ml of 0.155m sodium hydroxide (naoh), what is the molarity of the acid?

Given:

Volume of HCl (VHCl) = 25,0 ml = 0.025 L

Volume of NaOH (VNaOH) = 22.15 ml = 0.02215 L

Molarity of NaOH (MNaOH) = 0.155 M

To determine:

Molarity of HCl

Explanation:

Titration reaction-

HCl + NaOH →  NaCl + H2O

Based on the reaction stoichiometry:

1 mole NaOH requires 1 mole HCl

# moles of NaOH = VNaOH * MNaOH = 0.02215*0.155 = 0.003433 moles

# moles of HCl = # moles of NaOH = 0.003433 moles

Molarity of NaOH = 0.003433/0.025 = 0.137 M

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.

the answer is c.the valence of the atoms combine .