1.

A analysis of a pyrex glass showed 12.9% B_(2)O_(3), 2.2% Al_(2)O_(3),3.8%Na_(2)O,0.4%K_(2)O and remaining is SiO_(2). What is the ratio of Si to B atoms in the glass ? (At. Masses : Si = 28, B = 11, Al = 27, Na = 23, K = 39)

Answer»

Solution :`SiO_(2)" present in 100 g of glass"=100-(12.9+2.2+3.8+0.4)=80.7g`
`=(80.7)/(28+2xx16)"mole"="1.345 MOLES of "SiO_(2)`
`"= 1.345 mole of Si atoms"`
`=1.345xx6.023xx10^(23)" atoms"`
`B_(2)O_(3)" present in 100 g glass "=12.9 g=(12.9)/(2xx11+3xx16)"mole"="0.184 mole of "B_(2)O_(3)`
`=2xx0.184" mole of B atoms"`
`=0.368xx6.02xx10^(23)" atoms"`
`therefore"Si atoms : B atoms = 1.345 : 0.368 = 3.65 : 1 = 11 : 3"`


Discussion

No Comment Found

Related InterviewSolutions