PLEASDE PLE A SHELP What is the change in enthalpy of the first reaction below, given the enthalpies of the other two reactions? 2C(s) +0,(8) 200(g)
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C(s) +0,(g) - CO2(g) AH°-394 kJ/mol
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CO(s) +0,() CO2(g) AH° = -283 kJ/mol

Joseph has hypothesized that sound travels in waves. if he were following the scientific method, what should he do next? a. ask a question. b. test the hypothesis. c. study the results. d. tell other scientists about his hypothesis.

What type of reaction is shown below? check all that apply. 2h2o2 → 2h2o + o2 synthesis decomposition combustion

Answer asap need by wednesday morning explain how a buffer works, using an ethanoic acid/sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.