How many moles of Ca are in 1.25x1023 atoms? We used two conversion factors in this unit, they are provided below. It is your responsibility to know which conversion factor to use!

Avogadro’s number: 6.02x1023 atoms = 1 mole

Molar mass of calcium: 40.078 g Ca = 1 mol Ca

A. 3.12x10^21 mol

B. 0.21 mol

C. 3.12 mol

D. 0.21x10^21 mol

B. 0.21 mol

General Formulas and Concepts:

Math

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Chemistry

Atomic Structure

Using Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:

Step 1: Define

1.25 × 10²³ atoms Ca

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

Set up:                              Multiply:                            

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

0.207572 mol Ca ≈ 0.208 mol Ca

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