Resolving Dissolving and Understanding Particular Properties
THE REAL WORKSHEET!!!
We have learned that all matter has electrical properties. This means that matter is made up of positive and negative charges. Not all matter demonstrates its electrical properties in the same way or to the same extent. The electrical property of matter determines what will actually dissolve and when it will dissolve. Some solids dissolve in water because they have similar electrical properties of water. This continues the explanation as to why the wave bottle has two layers-it is not just about density!
As you discovered in the last lab “Particular Properties” only specific solids dissolved in water while others did not. The solids that did dissolve in water had electrical properties that were similar to water, while solids that did not have similar electrical properties as water did not dissolve. The rule is … “like dissolves like”. This means that substances that have similar characteristics or properties will mix and dissolve together, while unlike substances separate from each other (will not mix) to form layers. The solids that did dissolve in water were hard with high melting points and high conductivity. Which category was that?
The compounds from particular properties that did dissolve in water easily and conduct electricity are ionic compounds . Table salt is one of the most common ionic compounds.
Ionic compounds are pulled apart into smaller charged particles that are called ions (you may remember this word from a previous reading). Some of these particles have positive charges while other particles have negative charges due to the transfer of electrons while forming a bond. In this sense, the electrical properties of ionic compounds are LIKE water so they dissolve in water. Evidence of this can be found in the activity “Bending Water”. Water bent toward both positively and negatively charged object. Water demonstrates BOTH plus and minus charges, similar to ionic compounds.
Other compounds besides ionic compounds will dissolve in water if the substances have similar electrical properties to water. Other molecules that are like water are called polar covalent molecules because they have dipoles like water. Dipoles are made when a molecules shares electrons unequally while forming a bond. Substances like water and sugar fall into this category of “polar”. In Particular Properties it was evident that some dipoles were stronger than others, resulting in a different speed or ability to dissolve in water. Strong dipoles will dissolve quickly, while weak dipoles dissolve slowly. Polar substances are described as soluble or partially soluble in water, poor conductors and have a low to medium melting point.
Need to know more about dipoles? The word dipole can be broken into 2 smaller words “di” and “pole”, di = 2 (the 2 ends of the molecule) and pole = opposite charges that are found on either of the ends of the molecule. Some molecules are said to have a strong dipole which means that one end is pulling the electron when sharing much harder than the other; other molecules have weak dipoles because they are pulling almost equally. This is due to something called electronegativity. Substances that share electrons unequally have dipoles and are called polar, and substances without dipoles share electrons equally and are called nonpolar.

Finally, some substances will not dissolve in water, as they have DIFFERENT electrical properties than water. These substances are called non-polar covalent molecules . These molecules are not ionic or have dipoles, as they share electrons equally while forming a bond.
Substances like baby oil fit into this category. These substances are described as not soluble in water, have a low melting point and do not conduct electricity.
Matching
_____1. ion
_____ 2. ionic compound
_____ 3. solvation
_____ 4. covalent compound a. when a substance/compound is pulled apart
particles due to the interactions between it and the substance it is in. b. an “end” of a molecule that is positive or negative due to unequal sharing of electrons. c. a type of compound composed of strong but oppositely charged particles due to the transfer of electrons. d. a covalent compound composed of charged ends due to unequal distribution of charges.
_____ 5. polar covalent compound e. a covalent compound that does not have charged ends due to equal sharing of electrons.
_____ 6. nonpolar covalent compound f. a charged particle.
_____ 7. dipole g. a type of compound that can share or not share electrons equally.
True or False
_____ 1. Substances that are unlike each are soluble.
_____ 2. Substances that are like each other are soluble.
_____ 3. Ions are particles that are not charged.
_____ 4. Ions are particles that are charged.
_____ 5. Ionic compounds are composed of strong oppositely charged particles.
_____ 6. Ionic compounds are composed of weak oppositely charged particles.
_____ 7. Polar covalent compounds have dipoles.
_____ 8. Polar covalent compounds do not have dipoles.
_____ 9. Nonpolar covalent compounds do not share electrons equally.
_____ 10. Nonpolar covalent compounds share electrons equally.
_____ 11. Waxes and oils have dipoles, while water and salt do not.
______12.Waxes and oils don’t have dipoles, while water does.

Fill in the Blank – Words can be used more than once.
Ions
Polar covalent
Positive ionic nonpolar covalent negative solvation dipole(s) opposite
Same
Water like sugar salt oils
1. A particle that has either a ______________ or a ________________ charge are called_______________.
2. Ions are particles that make up ___________________ compounds. _______________ is an example of this kind of compound.
3. Water has ____________________ because it has a ________________ and a
_____________end. The charges on these ends are weak which makes water a
________________________ compound.
4. ______________________________ compounds don’t have an overall charge and
___________ is an example.
5. In the process of _____________________ salt an __________________ compound will dissolve in water a _____________________________ compound because the
__________________ charges attract each other.
6. The general rule of thumb for solvation is ________________ dissolve ________________.
Answer the Following
1. What 2 ions make up salt and what are their charges?
2. What are the 3 major types of compounds and their differences?
3. Why does salt dissolve in water? Explain with words or pictures.