Answer: The equilibrium constant is 
Explanation:
Initial concentration of
= 0.095 M
The given balanced equilibrium reaction is,

Initial conc. 0.095 M 0 M
At eqm. conc. (0.095-x) M (2x) M
Given : 2x = 0.0055
x = 0.00275
The expression for equilibrium constant for this reaction will be,
Now put all the given values in this expression, we get :


Thus the equilibrium constant is 
Answer : The density of an object is 0.93 g/mL
Explanation : Given,
Mass of an object = 3.8 g
Initial volume = 4.5 mL
Final volume = 8.6 mL
First we have to calculate the volume of an object.
Volume of an object = Final volume - Initial volume
Volume of an object = 8.6 mL - 4.5 mL
Volume of an object = 4.1 mL
Now we have to calculate the density of an object.
Formula used:

Now putting all the given values in this formula, we get:


Therefore, the density of an object is 0.93 g/mL