Chapter 5: Textbook Flashcards
What is a solution?
A homogenous mixture of substances composed of at least solute (the substance that is dissolved) and one solvent (what the solute is dissolved in)
What is a solute?
A substance that is dissolved, such as salt
What is a solvent?
The medium in which the solute is dissolved, such as water
Why do some mixtures appear opaque or translucent?
Because they contain undissolved particles large enough to block or scatter lightwaves. This would be called a heterogenous mixtureq
If you were to do a chemical analysis of a homogeneous substance, what would you find in terms of proportions?
The proportion of each chemical will remain the same, regardless of the size of the sample. Because of the idea that there is a uniform mixture of entities in a solution
Empirically, what would classify as homogeneous?
A solution that is uniform at the atomic and molecular levels
What state can solutes and solvents be in?
Solid, liquid or gas
In metal alloys such as bronze, what state is dissolving done in?
It is done in liquid form before the substance is put into solid form
What is the solution of gasoline composed of?
It is a mixture of many different hydrocarbons that form a solution at the molecular level
What is an example of a liquid dissolved in a liquid?
Methanol in water to make antifreeze
What is an example of a solid dissolved in a solid?
Tin in copper to make bronze
What is an example of liquids and solvents dissolving in a solvent other than water?
Solid iodine dissolved in ethanol (an alcohol)
How does a chemical formula represent a solute and solvent?
It specifies the solute by using its chemical formula and shows the solvent in parenthesis ex NH3(aq)
What would be the solute and solvent in this chemical formula? NH3(aq)
Ammonia gas (solute) dissolve in water (solvent)
What are the 2 ways that compounds can be classified as?
Electrolytes or nonelectrolytes
When are compounds electrolytes?
When their aqueous solutions conduct electricity
When are compounds nonelectrolytes?
If their aqueous solutions do not conduct electricity
How can the conductivity of a solution be calculated?
With a conductivity apparatus or an ohmmeter. It also shows if the solution is an electrolyte or nonelectrolyte
What type of solutions are usually electrolytes?
Highly soluble ionic compounds, including ionic hydroxides
What types of compounds are usually nonelectrolytes?
Most molecular compounds such as ethanol, with the exception of acids
Do acids conduct electricity?
Acids are molecular compounds but when dissolved in water they are conductive
What kind of solutions do ionic and molecular compounds form?
Neutral solution
What happens when a molecular compound is dissolved in water?
It creates a nonelectrolyte solution because the particles disperse electrically neutral particles through the solution. So it does not conduct electricity
What happens when ionic solutions are dissolved in water?
When the ionic compound dissolves, it dissociates into individual aqueous ions. The positive ions are surrounded by the negative ends of polar water molecules and vice versa.
What is dissociation?
The separation of ions that occur when an ionic compound dissolves in water
What is responsible for the properties of basic solutions?
Hydroxide ions
Why are Hydroxide ions responsible for properties of bases?
Because ionic hydroxides are compounds that dissociate into individual positive ions and negative hydroxide ions in a solution