The ethyl alcohol in "gasohol" burns to form CO 2 and H 2O. If the combustion reaction consumes 6.645 moles of C 2H 5OH reacting with excess O 2, how many grams of H 2O are formed

359.3 g

Explanation:

Step 1: Write the balanced combustion reaction

C₂H₅OH + 3 O₂ ⇒ 2 CO₂ + 3 H₂O

Step 2: Calculate the moles of water formed from 6.645 moles of ethyl alcohol

The molar ratio of C₂H₅OH to H₂O is 1:3.

6.645 mol C₂H₅OH × (3 mol H₂O/1 mol C₂H₅OH) = 19.94 mol H₂O

Step 3: Calculate the mass corresponding to 19.94 moles of H₂O

The molar mass of H₂O is 18.02 g/mol.

19.94 mol × 18.02 g/mol = 359.3 g

in the analysis of systems that involve fluid flow, we frequently encounter the combination of properties u and pv.

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.