2. Many calculations in chemistry will involve certain symbols, such as the symbol triangle or delta What does this symbol stand for or mean?
A. "The total"
B. "The change in"
C. "The unit"
D. "The formula"

B. "The change in"

I saw that symbol a lot in chemistry and physics so I immediately recognized it.

your answer would be a. 12.5 kg

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.