What actually happens when compounds are dissolved in solution?
You have probably seen the magical power of dissolving salt or sugar in water but you probably have never wondered what actually happened to the crystal looking water solid once it enters the liquid water.
As it was stated above in mixing solution rules, polar molecules will form solutions with other polar molecules. So if we were to look at NaCl in water, what actually happens?
Since NaCl is an ionic solid (non-metal with a metal), the cation(+) Sodium ion and the anion (-) chlorine atom dissociates or separates in solution. The subscript (aq) is then placed after to indicate that the ions have been dissociated in a water solution.
NaCl(s) à Na+(aq) + Cl+(aq)
The (aq) represents Aqueous or dissolved in water
If the NaCl or the ions are all separated once they are in solution, where do they go?
The cations and the anions orient and re-position themselves in a manner called the Solvation process.
The solvation process basically means that the positive ions will position themselves and attracted to the negative side of water while the negative ions will position themselves and attracted to the position side of water.
The solvation process: The above diagrams shows how the solute is dissociated and become attracted to the respective ends of the solvent.
- Describe and give examples of various types of solutions. Include: all nine possible types
- Describe the structure of water in terms of electronegativity and the polarity of its chemical bonds.
- Explain the solution process of simple ionic and covalent compounds, using visual, particulate representations and chemical equations. Include: crystal structure, dissociation, hydration
- Interpreting a a solubility curve of a pure substance in water and differentiate among saturated, unsaturated, and supersaturated solutions.
- Explain how a change in pressure affects the solubility of gases.
- Explain freezing-point depression and boiling-point elevation at the molecular level. Examples: antifreeze, road salt…
- Include: grams per litre (g/L), % weight-weight (% w/w), % weight-volume (% w/v), % volume/volume (% v/v), parts per million (ppm), parts per billion (ppb), moles per litre (mol/L) (molarity)
- Prepare a solution, given the amount of solute (in grams) and the volume of solution (in millilitres), and determine the concentration in moles/litre. (Molarity)
- Solve problems involving the dilution of solutions.
Include: dilution of stock solutions, mixing common solutions with different volumes and concentrations