The standard free energy change for a chemical reaction is -18.3kJ/mole. What is the equilibrium constant for the reaction at 87 degrees Celsius? (R=8.314J/K*mol)

Delta G = -Rtlnk

-18,300/8.314/360 = -6.114

It looks like you solved for ln K

They asked for K.

I assume your -18,300/8.314/360 means
-18,300/(8.314*360)

Never write fractions as a/b/c

To find the equilibrium constant (K) for the reaction, we can use the equation:

ΔG = -RTlnK

Where:
ΔG is the standard free energy change for the reaction,
R is the gas constant (8.314 J/K*mol),
T is the temperature in Kelvin, and
K is the equilibrium constant we want to calculate.

Given that ΔG is -18.3 kJ/mol and T is 87 degrees Celsius, we need to convert the temperature to Kelvin by adding 273.15.

T = 87 + 273.15 = 360.15 K

Substituting the values into the equation, we have:

-18,300 J/mol = (-8.314 J/K*mol)(360.15 K) ln K

Dividing both sides by -8.314*360.15:

-18,300/8.314/360.15 = ln K

Calculating this will give us the natural logarithm of K. Therefore, we need to exponentiate both sides of the equation to find K. The exponential form of ln K is e^(ln K) = K. So, we can calculate K by raising e (approximately equal to 2.718) to the power of the left side of the equation:

K = e^(-18,300/8.314/360.15)

Evaluating this expression will give you the equilibrium constant (K) for the reaction at 87 degrees Celsius.