Final Answer:
The number of moles of SiO₂ in a quartz crystal with a mass of 45.2 g is approximately 0.632 moles.
Step-by-step explanation:
In order to determine the number of moles of SiO₂ in the quartz crystal, we can use the formula:
moles = mass/molar mass
The molar mass of SiO₂ can be calculated by adding the atomic masses of silicon (Si) and two oxygen (O) atoms. The atomic mass of Si is approximately 28.09 g/mol, and for O, it is around 16.00 g/mol. Thus, the molar mass of SiO₂ is:
Molar mass of SiO₂ = 28.09 g/mo} + 2 x 16.00 g/mol = 60.09 g/mol
Now, we can substitute the given mass (45.2 g) and molar mass (60.09 g/mol) into the formula:
moles = 45.2g/60.09g/mol
After calculating, we find that the number of moles is approximately 0.632 moles.
This result indicates that in a quartz crystal weighing 45.2 g, there are approximately 0.632 moles of SiO₂ molecules. This calculation is essential in various scientific applications, providing a basis for understanding and manipulating chemical quantities in different materials.