How Much SiCl4 Results from 2.8g of Silicon with 50% Yield?

[a.a]

Homework Statement

The direct reaction of silicon with Cl_2 the yield of SiCl4 is 50%. How many grams of SiCl4 are obtained in the reaction of 2.8 g of silicon with excess chlorine?

Homework Equations

Si= 28.0855g
SiCl4= 169.8963g
Si + 2Cl2 --> SiCl4

The Attempt at a Solution

2.8g Si = (84.94815 g SiCl4/28.0855 g Si)* 2.8g Si
= 8.468 g SiCl4
= 8.5 SiCl4

Could someone please let me know if I made any mistakes?

 

[Borek]

2.8g Si = (84.94815 g SiCl4/28.0855 g Si)* 2.8g Si = 8.468 g SiCl4

This is obviously wrong - perhaps just what you wrote is wrong, as the final number looks OK. But for sure 2.8 g Si doesn't equal 8.468 g SiCl₄.

However - where is the yield percentage used? Have you forgot?

 

[a.a]

sorri, the way i wrote is is wrong, i ment to say that 2.8 Si produces 8.468 g SiCl_4
i used the percentage yeild in that i said 84.94815 g SiCl4 rather than 169.8963g

 

[Borek]

Use precentage as the last step, after you calculate correct stoichiometric amount. Numbers look OK.

 

[a.a]

do we still arive at the same answer though?

 

[Borek]

Yes. That's why I wrote that numbers look OK.