Pick one or more of the following combinations to investigate in this activity.
vinegar and baking soda (nahco3)
room temperature water and powdered washing soda (na2co3)
vinegar and table salt (nacl)
what chemical combination did you investigate?
did the observed temperature of the solution increase or decrease?
based on your observation, was the reaction endothermic or exothermic? explain your answer using complete sentences.
describe in detail the relationship between chemical bonds and energy. what must be true of the bonds for a reaction to be endothermic and what must be true for the reaction to be exothermic?

What’s the percent by mass of carbon in c10h14n2

The last few miles of the marathon are the most difficult for heather, her hair plastered to her head, sweat clinging to her arms, and her legs already feeling as if they had nothing left, just dead weight. after grabbing a cup of ice water, she feels the ice cubes smash against her nose as she gulps some cool refreshment and keeps on running. in these last few miles, the breeze kicks up and she finally feels some coolness against her skin. drips of sweat, once clinging to her forehead, now spill down, and heather feels more pain as the sweat flows into her eyes.which of the following is the most likely reason why the ice struck heather’s nose when she took a drink? a) water can function as a solvent. b) water can store large amounts of heat. c) water can moderate temperatures through evaporative cooling. d) the density of water decreases when it freezes. e) water has a cohesive nature.sweat remained on heather’s forehead and arms because of the a) high salt content of sweat b) cohesive nature of water c) ability of water to moderate heat d) high evaporative cooling effect of water e) ability of water to act as a solvent

Asample of tin (ii) chloride has a mass of 0.49 g. after heating, it has a mass of 0.41 g.  what is the percent by mass of water in the hydrate?   %