What is dimensional analysis? a. A systematic approach to problem solving that uses conversion factors to move from
one unit to another.
b. A ratio of equivalent values used to express the same quantity in different units; is
always equal to 1 and changes the units of a quantity without changing its value.

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.

a is the correct answer