the pupil weighed 2.8g of iron and 1.44g of sulfur powder. the materials were thoroughly mixed, sprinkled on a steel plate, and began to wait for the reaction to begin. However, it did not take place at room temperature. Why?

thats a little if u want the answer just look it up on google thats what i do haha : )

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.