How does the molecular weight of gas affect the k vaule

1- The lighter the molecule, the higher the K value.

2- when K value: is the ability of a material to conduct heat.
and materials with low thermal conductivities don't easily allow heat energy to pass through. 

3- The thermal conductivity should increase with decrease molecular weight. 

So as the molecular weight decreases the  K value be higher.

The answer to your question would be  h+ + cn– + li+ + oh– mc001-4.jpg li+ + cn– + h2o. the total ionic equation for the following reaction is  h+ + cn– + li+ + oh– mc001-4.jpg li+ + cn– + h2o.