In this experiment you will determine the solubility and solubility product of a sparingly soluble salt, potassium hydrogen tartrate, and also in four solutions containing a common ion.
INTRODUCTION
When a salt of low dissolubility dissolves in water, equilibrium is established between the solid solute and the dissolved ions. There are two terms used in discussing this condition. The first is solubility, which is the maximum amount of salt that will dissolve in a given amount of solvent (usually water) at a specified temperature. Solubility is usually expressed in units of molarity (moles/L), but sometimes g solute/ g solvent is used. The second term is a solubility product, Ksp. This is a special equilibrium constant for the dissolving of a salt in water. By convention the equation for the reaction is always written with the solid as the reactant, and the ions as products. For a general salt, AmBn, the equation would be:
The equilibrium constant for such a salt would be:
The solubility product expression matches the coefficients in the equilibrium equation, and that the solid is not included in the Ksp equation.
In this experiment, you will determine the Ksp for the sparingly soluble salt potassium hydrogen tartrate (also called acid tartarate or bitartrate). It dissolves in water to give potassium ions and hydrogentartrate ions according to the following equation:
It is soluble in water and N,N-dimethyl formamide; slightly soluble in methanol; very slightly soluble in ethanol, acetone, and acetonitrile; and insoluble in isopropanol and isopropyl
To accurately determine this, each trial will have recorded dependent and independent variables, constants and a control. The hypothesis being researched, indicates higher temperatures allow for a rapid rate of dissolution. In this particular case with someone needing Alka Seltzer, they will feel better faster if they use hot water to dissolve the medicine before
Observe the reaction and record how fast the Alka-Seltzer dissolves.
7. Place an Alka-Seltzer tablet into a second empty water bottle.
8. Pour 16 oz of room-temperature water into the bottle.
The goal of this experiment is to find out what is the identity of the unknown hydrate? To answer this question first, we should know what a hydrate, and how to identify a hydrate using the law of constant proportions. A hydrate is a pure substance because it contains water molecules embedded in its crystal structure that does not vary. By heating the unknown hydrate, we can calculate the mass of the hydrated, and the percentage of water in the hydrate.
Our original question was what is the effect of different types of water on
an Alka Seltzer tablet? What we were measuring was which type of water will make the tablet dissolve the quickest. Our hypothesis was the salt water would dissolve it the fastest, then the pond the second, and tap would take the longest. The results ended up being that the tap water would dissolve the tablet the fastest, then the pond water, and the the salt last. Our three controls are the amount of salt, the amount of water, and the size of the tablet.
In order to separate KNO3 and CuSO4, which are both soluble in water, recrystallization was used. The reason the two components can be separated through recrystallization is because of the temperature dependence of solubility, KNO3 is much more soluble in hot water and insoluble in cold water while CuSO4 is only slightly more soluble in hot water. When the filtrate was heated the solution was saturated with KNO3 but when the system was cooled, the KNO3 became insoluble and pure crystals reformed while CuSO4 stayed dissolved in the
To begin, the solubility of the unknown compound in water was tested. If the compound is soluble in water, it can be inferred that it is either a polar covalent or ionic compound.
During the standardization titration, there were two attempts made at dissolving the calcium carbonate. On the first attempt, sodium hydroxide was added along with the magnesium but would not dissolve completely. On the second attempt, an extra 5 mL of sodium hydroxide was added to help dissolve the calcium carbonate. After the solids dissolved over a heated stove, the magnesium was added. All of the water hardness comes from the Ca2+ of the calcium
The Study of Diffusion and Osmosis Using Deshelled Eggs
Maquita A. Dieufene
Jessica Thelwell(Partner)
10/09/2014
1611 Evening Lab
Introduction
It is quite simple to overlook the roles diffusion and osmosis play in daily life. If one has ever spent too much time in the pool and watched as their fingers begin to turn prune-like, that is an example of osmosis. Osmosis is simply defined as the movement of a concentrated solvent through a semi permeable membrane to a more concentrated solvent.(Biology Corner) Relating to the earlier example of osmosis, your body acts as the more concentrated solvent for the water to penetrate.
Diffusion is the exact opposite of osmosis.
So, how does salt alter a solution when it is dissolved into water?
When dealing with homemade ice cream “change phase”, “freezing point-depression”, and “temperature” are extremely important words to know. Temperature is the degree or intensity of heat present in a substance or object, measured in Fahrenheit or Celsius. Change phase is the transformation from one state (solid, liquid, or gas) to another without a change in chemical composition. Water can changed from solid, liquid, or gas under the right circumstances.
. SUPER HYDROPHOBICITY
Soumya Ranjan Sahoo (711CH1025)
NIT, Rourkela
Abstract:
Superhydrophobicity as a sensation has turned into an increasing focus of research and technological movement, where its key viewpoints span surface chemistry, chemical physics, and cellular biology. Hydrophobic particles have a tendency to be non-polar and, accordingly, incline toward other neutral molecule and non-polar solvents. Hydrophobic atoms in water frequently bunch together, shaping micelles.
Practical I: Acid-base equilibrium & pH of solutions
Aims/Objectives:
1. To determine the pH range where the indicator changes colour.
2. To identify the suitable indicators for different titrations.
3.
is this decision based on sound rationale? Comment briefly.
1. The use ethanol and water in a solvent pair is perfect do due to ethanol having a high solubility while the water has low
Introduction
Solubility is a chemical property that is measured in terms of the maximum amount of solute dissolved in a solvent at equilibrium. The resulting solution is called saturated solution. For example when a sample of sodium chloride solution in water is heated the behavior of the reaction is endothermic obstructing exothermic behavior. Another relationship that can be said about solubility is that the solubility of a solid substance increases as the temperature increases. The solubility of solutes is dependent on temperature.
