How many grams of SnO2 are required to produce 1.20x10^21 molecules of water?

0.150 grams

Explanation:

The balanced chemical reaction to obtain water from SnO₂ is:

SnO₂ + 2H₂ → Sn + 2H₂O

The mole ratio is:

         

Find the number of moles equivalent to  1.20× 10²¹ molecules of water, using Avogadro's number:

         

From the mole ratio, the number of moles of SnO₂ are half the number of moles of water. That is:

0.0019927 moles / 2 = 0.00099635 moles of SnO₂

Use the molar mass of SnO₂ to convert the number of moles to grams:

molar mass of SnO₂ = 150.71g/molmass of SnO₂ = 0.00099635mol × 150.71 g/mol = 0.150 grams.

The answer must be reported with 3 significant figures.

For cyclohexane compounds drawn in a chair conformation:   -axial bonds are vertical  -equatorial bonds are parallel to two bonds within the ring.  thus, as i assume the chair conformation is drawn:   -the x group is in an axial position, as are the five other vertical bonds.  -three axial bonds are on the top face of the ring  -the other three axial bonds are on the bottom face  the position of the second substituent on each ring carbon is equatorial.  gauche groups must be on an adjacent carbon such as carbon 6 and carbon 2, and also gauche groups are rotated by 60 degrees relative to each other.  drawing the newman projections for c1–c2 and c1–c6 aids in visualizing the groups that are gauche to the y group on c1.  click this link and watch some academic videos that may you more understand the topic 

What do you not know about it