Chapter U1.26, Problem 7E

Interpretation Introduction

Interpretation:

The process to separate NaCl and carbon from their mixture by using water is to be explained.

Concept introduction:

NaCl is an ionic compound. It can dissolve in water as it has ionic bond between atoms of sodium and chlorine. Carbon has network covalent bond between its atoms. So it cannot dissolve in water.

Answer to Problem 7E

Water can be used to separate NaCl and carbon from their mixture. First water is added to the mixture. NaCl dissolves in water and carbon does not. It settles to the bottom after some time. Then the solution is filtered to obtain carbon on the filter paper and salt solution as the filtrate. Salt solution can be evaporated to give salt.

Explanation of Solution

Chemical bonds hold the atoms together. There are many types of bonds between atoms and molecules. The bonding between atoms is so strong that the atoms remain connected to one another. NaCl is an ionic compound and it can dissolve in water as it polar solute. Carbon has network covalent bond between its atoms. So it cannot dissolve in water.

To separate NaCl and carbon from their mixture, water is added to the mixture. NaCl being an ionic compound will dissolve in water while carbon being network covalently bonded will not dissolve. After sometime, carbon will settle at the bottom. The clear salt solution can be either decanted or filtered. Carbon will be left behind or will remain on filter paper. Salt solution is obtained as a filtrate. NaCl can be obtained by evaporating the salt solution. Water will evaporate on heating and salt will be left behind.

Conclusion

Chemical bonds are responsible for certain properties of substances. Ionic bonds make compounds soluble in water while network covalent bonding does not allow substances to dissolve in water.