Tanya and Jon want to see if baking soda or sugar dissolves faster in water. Tanya adds 500 g of baking soda to 500 mL of room- temperature water. At the same time, Jon adds 500 g of table sugar to 500 mL of room temperature water. Both students start stirring the
mixture they made. In less than a minute, all of the sugar in Jon's mixture has dissolved. Tanya keeps stirring her mixture of baking soda
and water, but after 5 minutes, some of the baking soda still hasn't dissolved. Even if Tanya kept stirring her mixture all day, the remaining
baking soda would not dissolve. What explains this result?

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. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.

level 4 to level 2 : ))