What is the standard enthalpy change for the formation of water from its element
Practice Questions
Q1
What is the standard enthalpy change for the formation of water from its elements?
-285.83 kJ/mol
-241.82 kJ/mol
-393.5 kJ/mol
-572.4 kJ/mol
Questions & Step-by-Step Solutions
What is the standard enthalpy change for the formation of water from its elements?
Correct Answer: -285.83 kJ/mol
Step 1: Understand that the standard enthalpy change is the heat change when one mole of a compound is formed from its elements in their standard states.
Step 2: Identify the elements that make up water, which are hydrogen (H2) and oxygen (O2).
Step 3: Write the chemical equation for the formation of water: H2 + 1/2 O2 -> H2O.
Step 4: Look up the standard enthalpy change value for this reaction, which is -285.83 kJ/mol.
Step 5: Understand that the negative sign indicates that the reaction releases heat (exothermic reaction).
