A 1.67-g sample of solid silver reacted in excess chlorine gas to give a2.21-g sample of pure solid Agcl.The heat given off in t

Question

crimeas

2 months ago

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A 1.67-g sample of solid silver reacted in excess chlorine gas to give a2.21-g sample of pure solid Agcl.The heat given off in t

his reaction was 1.96 kJ at constant pressure.Given this information,what is the enthalpy of formation of AgCl(s)

Chemistry

2 answers:

alisha [2.9K] · Answer 1 · 2026-04-06T07:42:14+03:00

Mass of Ag = 1.67 g Mass of Cl = 2.21 g Heat released = 1.96 kJ Explanation: To find the enthalpy of formation of AgCl(s), we have the reaction: 2Ag(s) + Cl2(g) → 2AgCl(s). First, we need to calculate the moles of Ag and Cl from their masses. The atomic mass of Ag is 108 g/mol, thus moles of Ag = 1.67/108 = 0.0155 moles. The atomic mass of Cl is 35 g/mol, therefore moles of Cl = 2.21/35 = 0.0631 moles. Since Ag's moles are much less than Cl's, silver is the limiting reagent. Based on the stoichiometry of the reaction, the number of moles of AgCl produced equals 0.0155 moles. The enthalpy of formation of AgCl = 1.96 kJ/0.0155 moles = 126.5 kJ/mol. Hence, the enthalpy of formation is 126.5 kJ/mol.

alisha [2.9K] · Answer 2 · 2026-04-06T07:43:10+03:00

The value of enthalpy of formation for AgCl is -127.3 kJ/mol. To calculate the moles, we utilize the equation: Given mass of silver chloride = 2.21 g and its molar mass = 143.32 g/mol. Inserting values into the formula gives us the answer. The sign of heat follows a specific convention: it’s positive if absorbed and negative if released. To determine the enthalpy change in formation of AgCl, we apply the equation where the amount of heat released = -1.96 kJ and n = number of moles of AgCl = 0.0154 moles = enthalpy of formation for silver chloride. Therefore, the enthalpy of formation for AgCl comes to -127.3 kJ/mol.