Question #201294

DIRECTIONS: Solve the following.

1. Determine the number of atoms in 1.75 mol Al

2. Calculate the number of formula units in 25.0 mol NaNO3

3. Given 6.25 mol H O2 determine the number of molecules.

Expert's answer

Mole="\\frac{Mass}{Molar mass}"

Molarity= "\\frac{Mass of solute}{ volume in liters}"

Molality= "\\frac{moles of solute} {volume of solvent in kg}"

These are the common formulas related to moles that are used in chemical calculations.Â

1) When aluminum has 1.75 moles, we need to calculate the number of atoms in it. For calculating the number of moles, the value is multiplied by the Avogadro's number.

One mole=6.022Ã—10^{23}

Number of atoms="\\frac{1.75mol}{1mol}" Ã—6.022Ã—10^{23}atoms

**Number of atoms =1.05Ã—10**^{24}**atoms**

2) In sodium nitrate, 25.0 moles are present. To calculate the number of formula units in it, we need to multiply the moles value by Avogadro's number.

One mole=6.022Ã—10^{23}

Number of formula units ="\\frac{25.0mol}{1mol}" Ã—6.022Ã—10^{23}formula units

**Number of formula units =1.51Ã—10**^{25}**formula units**

3) In sodium nitrate, 25.0 moles are present. To calculate the number of formula units in it, we need to multiply the moles value by Avogadro's number.

One mole =6.022Ã—10^{23}

Number of molecules ="\\frac{6.25mol}{1mol}" Ã—6.022Ã—10^{23}molecules

**Number of molecules =3.76Ã—10**^{24}**molecules **

Learn more about our help with Assignments: Chemistry

## Comments

## Leave a comment