Two chemical reactions are shown: A. Ca(OH)2 - CaO + H2O
B. 4K + O2 + 2K20
Which statement is true?

A. Both are synthesis reactions
B. Both are decomposition reactions
C. A is a synthesis reaction, and B is a decomposition reaction
D. A is a decomposition reaction, and B is a synthesis reaction

Answer asap need to be answered 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.

The empirical formula of a compound is ch2o and its mass is 120 amu/molecule, what is its formula?

Which best describes the present-day universe? opaque, expanding very slowly, stars produce heavy elements transparent, expanding at an accelerated rate, stars produce heavy elements opaque, expanding at an accelerated rate, stars produce only hydrogen and helium transparent, expanding very slowly, stars produce only hydrogen and helium