The balanced reaction is:
<span>4Cr(s)+3O2 (g )= Cr2O3 (s)
Since we are not given the amount of any of the reactants, we assume we have one gram of chromium. Calculations are as follows:
1 g Cr ( 1 mol Cr / 52 g Cr ) ( 1 mol Cr2O3 / 4 mol Cr ) = <span>0.005 mol Cr2O3
</span></span>0.005 mol Cr2O3 (151.99 g Cr2O3 / 1 mol Cr2O3 ) = 0.7307 g <span>Cr2O3
</span>
Therefore, the theoretical yield for 1 gram of Cr is 0.005 mol Cr2O3 or 0.7307 g Cr2O3.
Forming oxygen by bubbling fluorine through water.
Answer: 
Explanation: The given chemical reaction is:

Equilibrium constant (Kc) in general is written as:
![K_c=\frac{[products]}{[reactants]}](https://tex.z-dn.net/?f=K_c%3D%5Cfrac%7B%5Bproducts%5D%7D%7B%5Breactants%5D%7D)
Note:- Coefficients are written as their powers
So, the Kc expression for the above reaction will be:
![K_c=\frac{[NO]^2[Br_2]}{[NOBr]^2}](https://tex.z-dn.net/?f=K_c%3D%5Cfrac%7B%5BNO%5D%5E2%5BBr_2%5D%7D%7B%5BNOBr%5D%5E2%7D)
Equilibrium moles are given for all of them. Let's divide the moles by given liters to get the concentrations.
= 0.040 M
= 0.0658 M
= 0.0217 M
Plug in the values in the equilibrium expression to calculate Kc.


The answer is force. The definition of a force is: A push or pull on an object.