Consider the following reactions. (Note: (s) = solid, (l) = liquid, and (g) = gas.)
½H2(g) + ½I2(g) → HI(g), ΔH = +6.2 kcal/mole
21.0 kcal/mole + C(s) + 2S(s) → CS2(l)
What type of reaction is represented by the previous two examples?
A: exothermic
B: endothermic

9. write the chemical equation for the following word equations. include symbols for physical states in the equation. a. solid zinc sulfide + oxygen gas -> solid zinc oxide + sulfur dioxide gas b. aqueous hydrochloric acid + aqueous barium hydroxide -> aqueous barium chloride + water

Butadiene undergoes a reaction at a certain temperature in the gas phase as follows: 2c4h6(g) --> c8h12(g) the following data were collected for this reaction: time (min) [c4h6] (m) 0 0.36 15 0.30 30 0.25 48 0.19 75 0. determine the order of the reaction and the rate constant. 1st order and k = 4.3x10 -4 s-1 1st order and k = 2.3x10-4 s-1 2nd order and k = 4.3x10-4 s-1 2nd order and k = 2.3x10-4 s-1 zero and k = 4.3x10-4 s-1

What is the percentage composition of carbon in the compound ch4