How many moles are in 15.5 g #SiO_2#?

Answer 1

About a 1/4 of a mole.

Silicon dioxide has a molar mass of #60.08# #g# #mol^-1#. What does this mean? It means that Avogadro's number of #SiO_2# units has a mass of #60.08# #g#.

I only need to divide the mass by the molar mass to determine the molar quantity of silicon dioxide:

#"Moles of silicon dioxide " = "Mass"/"Molar Mass"#

#=# #(15.5*cancelg)/(60.08*cancelg*mol^-1)# #=# #??# #mol#

It's all too easy to make a mistake, so solving the equation with units included helps me avoid making mistakes. Should I divide or multiply? The fact that the calculation returned an answer in moles convinces me that I made the right decision.

What is silicon dioxide and how is its molar mass determined?

By signing up, you agree to our Terms of Service and Privacy Policy

Answer 2

Olivia Anton

To determine the number of moles in 15.5 g of SiO2, we first need to find the molar mass of SiO2. The molar mass of Si is approximately 28.09 g/mol, and the molar mass of O is approximately 16.00 g/mol.

Molar mass of SiO2 = (1 * molar mass of Si) + (2 * molar mass of O) = (1 * 28.09 g/mol) + (2 * 16.00 g/mol) = 60.09 g/mol

Now, we can use the formula:

moles = mass / molar mass

moles = 15.5 g / 60.09 g/mol ≈ 0.258 moles

Therefore, there are approximately 0.258 moles of SiO2 in 15.5 g.

By signing up, you agree to our Terms of Service and Privacy Policy

Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.