mole is the standardized form of molarity
<u>Answer:</u> The value of equilibrium constant for the net reaction is 11.37
<u>Explanation:</u>
The given chemical equations follows:
<u>Equation 1:</u> ![A+2B\xrightarrow[]{K_1} 2C](https://tex.z-dn.net/?f=A%2B2B%5Cxrightarrow%5B%5D%7BK_1%7D%202C)
<u>Equation 2:</u> ![2C\xrightarrow[]{K_2} D](https://tex.z-dn.net/?f=2C%5Cxrightarrow%5B%5D%7BK_2%7D%20D)
The net equation follows:
![D\xrightarrow[]{K} A+2B](https://tex.z-dn.net/?f=D%5Cxrightarrow%5B%5D%7BK%7D%20A%2B2B)
As, the net reaction is the result of the addition of first equation and the reverse of second equation. So, the equilibrium constant for the net reaction will be the multiplication of first equilibrium constant and the inverse of second equilibrium constant.
The value of equilibrium constant for net reaction is:

We are given:


Putting values in above equation, we get:

Hence, the value of equilibrium constant for the net reaction is 11.37
Lithium's atomic weight is 6.94 g/mol.

Need anything else?
Answer:
They can be dated using radioactive carbon. But for rocks older than 50 thousand years they look for layers of igneous rock or volcanic ash above and Bellow the layer of rock/fossil.