The molar mass of a substance is the mass of one mole of that substance.
M(Molar Mass)=(mass of solute)/(molality × kg solvents in solution);
Freezing point depression is a colligative property observed in solutions that results from the introduction of solute molecules to a solvent. The freezing points of solutions are all lower than that of the pure solvent and are directly proportional to the molality of the solute.
∆T=T_solvent-T_solution
∆T=m × K_f
If ionic solid is added to water, ions attract to the water molecules and interfere with the formation of the large network solid, ice. In order to achieve a solid, the solution must be cooled to an even lower temperature.
In order to fulfil the labs purpose, the lab was split into two parts. The first part consisted of measuring and determining the freezing point depression of the solution water. The second part consisted of measuring and determining the freezing point depression of a solution that consisted of water and an unknown solute.
The freezing point depression constant for water that was experimentally determined in this analysis was 0.0479 °C/m, which was derived from the slope of the trend line in Figure 4. This is significantly lower than the constant stated in the literature of 1.86 °C/m.1 The freezing point temperature determined via cryoscopy should have been much lower in the high sucrose concentration solutions.
The objective of the experiment “Keeping it Liquid” was to figure out what it takes to keep a compound in a liquid form which caused a phase change. A phase change is when a substance changes from one state or phase to another. There are three main phases that normally occur and they are called Evaporation, Deposition, and Melting. Evaporation is where a liquid changes to a gas. An example of evaporation is when water drops form on the glass of a cold drink on a warm day. Deposition is where a gas vapor goes directly into the solid phase without becoming a liquid first. An example of Deposition often occurs on windows during the winter months. While Melting is where a solid turns into a liquid. Melting occurs when ice turn into a liquid when
The freezing point constant (Kf) of water is 1.86 °C m-1. Each mass amount and Van’t Hoff factor was calculated then analyzed in a table.
Other substances that dissolve in water also lower the freezing point of the solution. The amount by which the freezing point is lowered depends only on the number of molecules dissolved, not on their chemical nature. This is an example of a colligative property. In this project, you'll investigate different substances to see how they affect the rate at which ice cubes melt. You'll test substances that dissolve in water (i.e., soluble substances), like salt and sugar, as well as substances that don't dissolve in water (i.e., insoluble substances), like sand and pepper. Which substances will speed up the melting of the ice?
Tanya Golash-Boza illustrates a personal life experience about the video of a baby who was having health issues because his mother was deported, and he kept rejecting the bottle. Surprisingly many comments on the video expressed hate towards the mother for being immigrant, and towards the baby for now being the orphan son of an immigrant. Many Americans have developed hate against immigrants because the government has created a stereotype of them as burdens and deviates. Politics and society focus on how immigrants can affect the economy or the country's security, creating a common feeling of contempt. Focus in the material issues has faded the human side of some members in society. The government forgets that immigrants are humans with rights, friends and family bonds. Any enacted law will affect
Aqueous solutions of ionic substances will be experimented with in this Ionic Reactions lab. Aqueous solutions are solutions that water is solvent. After ionic substances dissolve in water, ions separate and become surrounded by water molecules. When these ion separate, its called dissociation.
Purpose: The purpose of this laboratory was to gain an understanding of the differences between the freezing points of pure solvent to that of a solvent in a solution with a nonvolatile solute, and to compare the two.
Lab 1 also teaches us the importance of molecular weight of a substance and how to use that to find the amount of moles of that substance in a solution. For example; in exercise 3 we were asked to weigh 8 grams of sugar and then calculate how many moles of sugar it really was. Using the molecular weight of sugar (C = 12.01 grams/mol, H = 1.008 grams/mole, O = 15.00 grams/mole). We were then able to use this molecular mass of the sugar that we then had to use to calculate and determine the molarity of the sugar
3. The volume of a fixed mass of a liquid sample increases as the temperature rises from 20 to
The first step is the separation of the solid crystals back into separate ions, a positive ammonium ion and a negative nitrate ion. The break these ionic bonds requires a lot of energy which means heat must be taken from the surrounding water. The second step the water molecules, which are H2O, are attracted to the ions and attach themselves to the ions. The second step actually causes heat to be produced to the surrounding liquid mixture. .Even
Molar Mass is basically in grams per mole for example salt has a molar mass of 5.8g per mole. The mass of an element refers to 6.0221415x1023 molecules of the substance. Molar Mass helps us figure out how many grams per mole we need to do this project and it helps us know how much we need to put into the solution. If you don’t Find
Intermolecular forces hold molecules together when they are in solid or liquid state. However, water has the ability to dissociate many salts and ionic compounds. This is called dissolving. When NaCl is added to water, it dissociates into the ions; Na+ and Cl- . The positive sodium ions are surrounded by the slightly negatively charged part of water molecules (i.e. oxygen) in the water molecules and the negative chlorine ions are surrounded by the slightly positively charged part of water molecules (i.e. the hydrogen). The kinetic energy of the sodium chloride molecules increase with temperature. This destabilizes the solid state that it is currently in. This increased motion means that the molecules are less able to hold together and as such they dissolve at faster rates and larger amounts.
In the experiment I performed it was proven that, the moles of a solute, the volume of the solvent, and the molarity of an aqueous solution share a mathematical relationship. Solutions, solutes and molarity are all terms that are crucial to chemistry. A solution is defined as a liquid mixture in which the solute is distributed into the major component, and a solute is defined as the minor component within a solution. The molarity of a solution is the number of moles of solute per liter of solution and it is used to express the concentration of a solution. Both the solute amount and the solution volume can be determined in experiments to aid finding the solution concentration or molarity of a substance that they are included in. I state confidently
It is suspected that the freezing point is 64.1oC. Due to the short temperature plateau, It is difficult to determine if the freezing point occurs at during the interval (6:00-6:10). However, it appears to be have been the most reasonable determination for freezing point in comparison to the rest of the plot.