## dddan 3 years ago in the reaction of Si+2Cl yields SiCl4 in this reaction 0.507 mole of SiCl4 is produced how many moles of molecular chlorine were used in the reaction? please explain.

1. Ahaanomegas

$\text{Si} + 2\text{Cl} \rightarrow \text{SiCl}_4$Is this equation balanced? No! Why? Because the problem, as posted, is incorrect. Chlorine gas must be diatomic: Cl_2. After doing that, the equation is balanced. From here, use the coefficient ratios for mole ratios and it should be easy. Note, from the balanced equation, 2 moles of chlorine are required to form 1 mole of SiCl_4. If you still need help, let me know. I'll complete the solution for you. :D

2. dddan

thanks, can you show me?

3. Ahaanomegas

Sure. Do you see how 1 mole of SiCl_4 is formed from 2 moles of chlorine gas? Once you see that, you just do .507*2. :)

4. dddan

yup got it. thank you!

5. Ahaanomegas

No problem! :D

6. dddan

how do you balance out $O _{2}+NO \rightarrow 0_{2}+NO _{2}$

7. Ahaanomegas

You cannot. The O_2s cancel out and NO -> NO_2 is nonsense. Did you mean something else?

8. dddan

yea it O(3)+NO yields O(2)+NO(2)

9. Ahaanomegas

Oh. $O_3 + NO \rightarrow O_2 + NO_2$Yep, the 3 is hard to read as a subscript. There are 3 Os on the LHS and 4 Os on the RHS. Try balancing the Os. Put a 2 on the O3 and 3 on the O2. You get: $2O_3 + NO \rightarrow 3O_2 + NO_2$Now, there are 7 Os on the LHS and 8 Os on the RHS. Notice, here, that you can keep trying what you want but keeping the Ns balanced means keeping the Os imbalanced. The equation cannot be balanced. See here: http://www.gregthatcher.com/Chemistry/BalanceChemicalEquations.aspx