Chapter Seven: Solutions Flashcards
Normally, the body maintains a homeostasis of fluids and ______________. Conditions that alter the composition of body fluids can lead to _________, __________ or ________.
To halt the disease process and establish homeostasis, a patient may be given ______ _______ therapy.
electrolytes
convulsions, coma, death
intravenous fluid therapy
What is OSMOSIS?
Water flows in and out of the cells of the body
What is DIALYSIS?
Small particles in solution as well as water diffuse through semipermeable membranes.
The kidneys utilize OSMOSIS and DIALYSIS to regulate the amount of _______ and ___________ that are excreted.
Water and electrolytes.
What is a SOLUTION?
A homogeneous mixture in which one substance called the SOLUTE is uniformly dispersed in another substance called the SOLVENT.
Because the SOLUTE and the SOLVENT do not react with each other, they can be mixed in ______________ _______________.
varying proportions
Usually, the SOLUTE is the substance present in the _______ amount, whereas the SOLVENT is present in the ________ amount.
smaller
larger
In a solution, the particles of the SOLUTE are __________ dispersed among the molecules within the SOLVENT.
evenly
Which of the following may SOLVENTS and SOLUTES be: solids, liquids, gases?
All three
__________ is one of the most common SOLVENTS in nature.
Water
What is a POLAR SOLVENT? (use the example of water)
In the H2O molecule, an oxygen atom shares electrons with two hydrogen atoms. Because oxygen is much more electronegative than hydrogen, the O-H bonds are POLAR.
In each polar bond, the oxygen atom has a partial negative charge and the hydrogen atom has a partial positive charge.
Because the water molecule has a BENT shape, water is a POLAR SOLVENT
The _____________ between SOLUTE and SOLVENT will determine whether or not a solution will form.
A solution forms when _________________.
Such attractions only occur when the solute and the solvent have similar ____________.
Interaction
A solution forms when there is sufficient attraction between the particles of the solute and the solvent, which provides energy to separate the particles.
Polarities
SOLUTIONS with IONIC and POLAR solutes (use NaCl as an example):
There are __________ solute-solute attractions between positively charge Na+ ions and negatively charged CL- ions.
When NaCl crystals are placed in water, the process of ___________ begins as the partially _________ oxygen atoms in water molecules attract Na+ ions and the partially ________ hydrogen atoms in other water molecules attract CL- ions.
As soon as the Na+ and Cl- ions form a solution, they undergo ___________ as water molecules surround each ion. This diminishes their attraction to other ions and keeps them in solution.
The energy needed to form the solution is provided by the strong solute-solvent attractions between _____________ and the ______________.
strong solute-solute attractions
DISSOLUTION; negative, positive
HYDRATION
The energy needed to form the solution is provided by the strong solute-solver attractions between Na+ and Cl- ions and the polar water molecules.
See the equation for the formation of the NaCl solution on page 249.
A POLAR COVALENT COMPOUNDS such a methanol (CH3-OH) is soluble in water because ______________.
because methanol has a polar -OH group that forms hydrogen bonds with water.
Compounds containing NONPOLAR molecules such as iodine (I2), oil or grease do not dissolve in water because _______.
NONPOLAR solutes require ____________ solvents for a solution to form.
The _________ of a solute and a solvent must be similar in order to form a solution.
because there are essentially no attractions between the NONPOLAR solute and the POLAR solvent.
See Table 7.3 on page 249- possible combinations of solutes and solvents.
Solutes can be classified by their ability to conduct an electrical current.
When solutes called ELECTROLYTES dissolve in water, they separate into ions forming solutions that are __________ to conduct electricity.
When NONELECTROLYTES dissolve in water, they dissolve as molecules, not as ions and the solutions formed are _________ to conduct electricity.
ELECTROLYTES: able to conduct electricity
NONELECTROLYTES: NOT able to conduct electricity.
NOTE- to test solutions for the presence of ions, an apparatus is used that consists of a battery and a pair of electrodes connected by wires to a light bulb. The light bulb glows when electricity can slow, which can only happen when electrolytes provide ions that move between the electrodes to complete the circuit.
All ELECTROLYTES under _____________, in which some or all of the solute that dissolves produces ions.
DISSOCIATION
For a STRONG ELECTROLYTE, such as NaCl, there is _________ % dissociation of the solute into ions. The light bulb is ______.
100%; very bright
In an equation for dissociation of a compound in water, the charges must _________.
the charges must BALANCE.
See equation on page 251
What is a WEAK ELECTROLYTE?
…a compound that dissolves in water mostly as molecules. Only a few of the dissolved molecules separate, producing a small number of ions in solution.
Electrical current is not conducted as well as solutions of strong electrolytes.
See the equation on page 251.
What happens to a NONELECTROLYTE when it dissolves in water?
It dissolves only as molecules which do not separate into ions. These solutions do NOT conduct electricity.
See the chart on page 252- classification of solutes in aqueous solution.
What is an EQUIVALENT (Eq) ?
Body fluids contain a mixture of several electrolytes. We measure each individual ion in terms of an EQUIVALENT (Eq), which is the amount of that ion equal to 1 mole of positive or negative electrical charge.
Ex: 1 mole of Na+ ions and 1 mole of Cl- ions are each 1 equivalent because they each contain 1 mole of charge. For an ion with a charge of 2+ or 2-, there are 2 equivalents for each mole.
See Table 7.5 on page 252- equivalents of electrolytes
