20.0 mL of 1.00 M LiF is added to 15.0 mL of 1.50 M LiF, then an additional 50.0 mL of water is added.42.0 g of solute KCl (molar mass = 113.7 g/mole) is placed into 100 mL total solution.How many grams of sucrose (molar mass = 342.3 g/mole) are required to make 125 mL of solution which is 0.150 M? ( Answer: 6.42 g).What is the final molarity of the solution? 25.0 mL of a 0.125 M solution of KCl is mixed with 15.0 mL of a 0.440 M solution of KCl, then an additional 20.0 mL of water is added.How many mL total volume of solution must be produced to make a 0.220 M solution using 1.00 g of the solute LiF (molar mass = 25.94 g/mole)?.How many grams of sucrose ( C 12H 22O 11, molar mass = 342.3 g/mole) are required to make 500 mL of a solution that is 0.1500 M?.25.00 grams of solute NaCl (molar mass = 58.44 g/mole) is dissolved in a 250 mL volumetric flask.For calculation purposes, we will assume our volumetric flasks provide a volume accurate to ± 0.1 mL. To prepare a solution of the proper molarity, one weighs out the appropriate mass of solute to produce the correct number of moles, transfers it to the volumetric flask, fills the flask to the base of the neck, dissolves the solute, then fills the flask to the calibration mark etched in the neck. Volumetric flasks are specifically calibrated for a variety of solution volumes (among the most common specific volumes are: 5 L, 2 L, 1 L, 750 mL, 500 mL, 250 mL 100 mL, 50 mL 25 mL and 10 mL). This is due to the utility of the volumetric flask in the laboratory. Molarity is probably the most commonly employed of all solution concentration units. The thermodynamics of the solution process are governed by intermolecular forces. But a mixture of 2.00 grams ethanol (molar mass 46.0 g/mole) with 1.00 grams water (molar mass 18.0 g/mole) has a 1.28/1.00 ratio of solvent water to solute ethanol. For instance a mixture of 2.00 moles of ethanol with 1.00 mole of water has a 2.00/1.00 ratio of solvent ethanol to solute water. The total number of atoms or molecules of each component must be known in order to distinguish the solvent from the solute. The focus of our study will be solutions with water acting as solvent, or aqueous phase solutions. As Table 1 demonstrates, solutions can be formed from matter in a variety of phases. A homogeneous mixture of two components is called a binary solution, three components trinary, etc. A solution may contain several solutes, but only one solvent. In normal laboratory situations, the solvent is present in an overwhelming proportion, so that on average solute molecules interact to a much greater extent with a solvent "cage" than with other solute molecules.
The two principle components of a solution are the solvent and the solute, with the simple definition that the solvent is the most abundant component and the solute is present to a lesser extent. Now that the distinction has been made between these two types of systems, the rest of this lesson will focus on solutions. An emulsion is a dispersion of liquid in liquid (such as milk). An aerosol is a dispersion of either liquid in gas (such as fog) or solid in gas (such as smoke). A sol is a dispersion of a solid in a liquid (such as muddy water). The names of suspensions vary depending on the physical state of the substances involved. Because of this uneven distribution, a light beam passing through a suspension will demonstrate net scattering of light, called the Tyndall effect (This is used in the laboratory to distinguish suspensions from true solutions). In contrast, there exist non-homogeneous or disperse systems, which are formed by a suspension of small particles of matter (called colloids).
A consequence of this balanced proportionality is that light passing through a transparent sample of solution will scatter uniformly, so that the beam appears to pass straight through. By homogeneous, it is meant that random sampling of any region of a solution would result in the same ratio of components, no matter where that sample is taken. Introduction- Solutions and Their PropertiesĪ solution is a mixture of two or more components which is homogeneous throughout. Model of an Electrolyte in Aqueous Solution