For which entalphy changes is the value of ΔH always negative? 1- combustion
2-hydration
3-solution

( the answer choices is a, b,c, d)
a) 1,2 & 3 are correct
b) 1 & 2 are correct
c) 2 & 3 are correct
d) 1 only is correct

Explain why pure hydrogen cyanide does not conduct electricity, but become a conductor when it is dissolved in water? (at room temp, pure hcn exists as a volatile liquid)

Predict the relative bond lengths of the three carbon-oxygen bonds in the carbonate ion (co2−3). what would you expect the charge to be on each oxygen? match the words in the left column to the appropriate blanks in the sentences on the right. make certain each sentence is complete before submitting your answer.

A250 g sample of water with an initial temperatureof 98.8 closes 6500 joules of heat. what is the finaltemperature of the water?