Chapter 10, Problem 190A

Interpretation Introduction

Interpretation:

Amount of CoCl₂.6H₂O needs to be determined to get Avogadro’s number of particles.

Concept introduction:

One mole of any substance contains Avogadro’s number of units.

Answer to Problem 190A

238 g of CoCl₂.6H₂O will contain Avogadro’s number of particles.

Explanation of Solution

Atomic mass of Co, Cl, O and H are 59 g, 35.5 g, 16 g and 1 g respectively.

Taking the sum of all atomic mass molar mass

$\begin{array}{l}=(59+2\times 35.5+12\times 1+6\times 16)\text{g/mol}\\ =(59+71+12+96)\text{g/mol}\\ =238\text{g/mol}\end{array}$

Thus, CoCl₂.6H₂O has molar mass=238 g/mol. To get Avogadro’s number of particles 238 g of CoCl₂.6H₂O must be taken.

Conclusion

Thus, 238 g of CoCl₂.6H₂O must be measured out in a container to have exactly Avogadro’s number of particles.