Distillation Distillation is used to remove impurities from a mixture – one component of which must be a liquid. Boiling points are utilized in determining the identity of the unknowns. Types of distillation include
Aim The purpose of this experiment was to use fractional distillation technique to separate cyclohexane and toluene. Background Information Distillation is a technique which is used for separating two or more volatile products based on differences in their boiling points. Distillation can be used to separate a volatile solvent from a non-volatile product and separate a volatile product from non-volatile impurities. Simple distillation consists of a round-bottom flask, a distilling head, a condenser, an adapter and a receiver which are used to separate compounds where one is considerably more volatile than the other compound. This distillation is performed in one step.
Membrane separation technologies are among the most promising processes in water purification regarding their low energy consumptions. Membrane distillation (MD) is a thermally driven separation process in which liquid feed is evaporated at the feed/membrane interface and is transported through a hydrophobic microporous membrane[1–4]. The hydrophobic character of the membrane allows only volatile components to enter the pores. The differences of the vapour pressures across the membrane is the driving force of the process[5,6]. In comparison with other conventional technologies, membrane distillation benefits from low operational temperature and pressure and therefore low energy requirements.
Marigona Krasniqi 15 October 2015 Contemporary Science: Chemistry Lab assignment Gas Laws Lab Part 1 – The effect of temperature on gas volume Problem: Which gas law describes these results (Paper assignment)? Observation/ Research: Charles’s Law According to Jacques Charles, “if the temperature of the gas increases, the volume of the gas also will be increased or other way around.” (Charles). This statement describes Charles Law. According to this law, “the Volume and Temperature are directly proportional and pressure is held constant” (Charles). This shows that V/T = k, where k is constant.
A volatile liquid can be easily converted to its gaseous state, the gas that forms from vaporization is known as vapor and it is assumed to behave as an ideal gas. One of the properties that characterize a volatile liquid is determination of its molar mass. Dumas method also known as the vapor density method uses the vapor density of the unknown volatile liquid in determining its molar mass. The major assumptions of these methods are the substance behaves ideally. The molar mass of a volatile liquid can be obtained by measuring the temperature, pressure, mass, and volume in a gaseous state.
Methods of purification – Reflux and Distillation There are many ways of purification however reflux and distillation are two widely used methods. Having a similar apparatus makes it simple and easy to use both methods together. Heating under reflux allows a reaction mixture to be heated for a set amount of time without loss of products, reactants or solvent. Distillation is done to refine or isolate the substances from each other. When preparing an ester (an organic compound) the reactants are heated together under reflux so any material that evaporates is condensed and returned to the mixture.
It also confirmed the idea that molar mass of a solution could be determined through the freezing point depression formula as long as one knows the freezing point depression constant of the solvent used, the mass in kilograms for the solute-solvent mixture, and the change in freezing point from the addition of a solute. Lab Questions: What is the freezing point for lauric acid? What is the melting point for lauric acid? The freezing point for lauric acid in this experiment was 43℃. The melting point for lauric acid in this experiment was 50℃.
Fractional distillation is a separation technique used to separate two liquids with different boiling points and keep the liquid. To do this, we set it up just like the distillation lab with the 10-15mL in the test tube over the fire and the tube leading the the test tube in the beaker. The first time you go through, the same test tube is left in the whole time but you must record the temperature around every 10-15 seconds using your labquest. You then find two places where the temperature is consistent for a few seconds, this is your plateau. The second time you go through, change out the test tubes as soon as you get to your first plateau, this liquid is liquid one.
The equation can be further developed as: = k Although, Gay-Lussac's Law is also commonly written as: = Dependent variable: Pressure, using the unit Pascal (Pa), is measured using the pressure gauge that is a part of the Absolute Zero Apparatus. Pressure is measured to further investigate the relationship between temperature and pressure. Controlled variables: 1. The volume of gas inside the sphere, as it was closed and must remain constant in order for the readings to be accurate, as if it is not closed, the pressure will be affected by the room’s pressure. 2.