Normally the capital ÎGo° for a reaction would be determined at standard temperature with each reactant at a concentration of 1 M. Letâs assume that the 1 M 2-PG solution will reach the same equilibrium ratio that would be observed under standard conditions. The enzyme enolase catalyzes the conversion of 2-PG to phosphoenolpyruvate (PEP) in living systems. You find that when you add enolase to your 2-PG solution it reaches an equilibrium with 0.68M PEP and 0.32 M 2-PG. What is the capital ÎGo° for this reaction? Use R= 1.987 cal/mol. K

a. +559 cal/mol
b. - 559 cal/mol
c. +379 cal/mol
d.-379 cal/mol

d.-379 cal/mol

Explanation:

ΔG = ΔG⁰ + RT ln K

for equilibrium ΔG = 0

ΔG⁰ + RT ln K =0

ΔG⁰   =  -  RT ln K

PG ⇒ PEP

K = [ PEP ] / [ PG ]

= .68 / .32

= 2.125

ΔG⁰   =   - 1.987 x 273 x  ln 2.125

= - 409 Cal / mole

Option d is the nearest answer .

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6