Question

How many moles are in 5.4 x 10-7 grams of silicon dioxide, SiO2 ?

Answer 1

there are
`\sf 9*10^(-9)` moles in grams
`\sf 5.4 * 10^(-9)` of silicon dioxide.

Step-by-step explanation:

`\boxed { \boxed{ \sf moles = \sf{(mass)/(Mr)} }}`

we should know that:

• 
  `\sf molar \ mass \ of \ SiO2 = 60`

• 
  `\sf given \ mass \ of \ SiO2 = 5.4 * 10^(-7)`

using the formula:

`\sf moles = (mass)/(Mr)`

`\sf moles = (5.4*10^(-7))/(60)`

`\sf moles = 9*10^(-9)`