Chemical Forums

Chemistry Forums for Students => High School Chemistry Forum => Topic started by: danny411 on May 31, 2009, 03:52:26 PM

Title: two small problems
Post by: danny411 on May 31, 2009, 03:52:26 PM

ok,

Im not sure how solid sulfur breaks down


Heres the formula

Al +S8-->3

here's what i got

8Al +3S8-->8Al2S3

other one im working on so ill post it later

thanks again dan

Title: Re: two small problems
Post by: danny411 on May 31, 2009, 04:23:00 PM

second one

an alloy has gold and silver in it. It is 9.35g and .654cm^3

gold is 19.3 g/cm^3 and silver is 10.5g/cm^3

calculate the percentage mass of gold in the alloy

I forget how to do it

Au=.654cm^3 X 19.3 g/cm3 =12.6g

9.35/12.6 x100=74 %

Title: Re: two small problems
Post by: danny411 on May 31, 2009, 10:28:31 PM

got the second one

.654cm3=x/19.3 +9.35-x/10.5

.654(19.3)(10.5)=10.5 x +9.5(19.3)-19.3x

etc.