a typical pyrex glass contains 12.9% of b2o3 and 80.7% of sio2 (by weight) besides other oxides (al2o3 , na2O , k2O) what is the weight ratio of silicon to boron in the glass ( atomic weight si=28.1 b=10.8)?

Question

a typical pyrex glass contains 12.9% of b2o3 and 80.7% of sio2 (by weight) besides other oxides (al2o3 , na2O , k2O) what is the weight ratio of silicon to boron in the glass ( atomic weight si=28.1  b=10.8)?

anonymous · Answer

options are  9.32:1        9.76:1       9.29:1     9.43:1

anonymous · Answer

the answer is 9.43:1 but i dont know to solve it

anonymous · Answer

Empirical Formula question 

$$B_{2}O_{3} : SiO_{2}$$
$$69.7 : 60.1$$
( find the molecular mass of each....)

and then find their percentage like for example ratio of B203
$$\frac{12.9}{100} \times 69.7= 9$$

then for SiO2
$$\frac{80.3}{100} \times 60= approximately.. u ..get.. 48..but .$$
$$according.2..ur..answer..u.. can..assume ..\it..as..43:)$$

anonymous · Answer

AND forgot to mention....the other compounds they dont make a big issue (in the multiple choic...coz all of them have the number "1"

anonymous · Answer

take a 100 g sample...12.9 g of b2o3 will be there...find the mass of b in it....similarly find for Si and thus find the ratio..

anonymous · Answer

can u solve the mass for b plzz just an example

anonymous · Answer

|dw:1336476613452:dw| n gives the no of moles of b2o3...multiply it by molar mass of B times 2 to bet mass of total B atoms in terms of X which is approx X/70 (i took x g sample instead of 100g) ....similarly do for Si and cancel out x in thee ratio...