CHE 111 Laboratory 3 Hydrates Introduction Hydrates Water molecules combine with the molecules of certain substances, forming loose chemical combinations called hydrates. An example of a hydrate is MgSO4•7H2O. This formula means 7 water molecules are loosely attached to a magnesium sulfate molecule. Other examples of hydrates are Na2SO4•10H2O and Ba(OH)2•8H2O. When the hydrate is heated, it easily loses water molecules attached and becomes an anhydrous salt.
If the sample was to re-colloid, it would easily wash right through the filter, causing the analytical results to be low. Once the precipitate is dried, the silver and chlorine can be separated by simply being in the presence of light, illustrated in the below equation: AgCl(s) → Ag(s) + 1/2Cl2(g) This decomposition happens quite quickly in strong light; however, it mostly occurs on the surface of the precipitate because its opaqueness protects all the material below the surface. If there are excess silver ions during the decomposition, another reaction may occur: 3Cl2(g) + 3H2O(l) + 5Ag+(aq) → 5AgCl(s) + ClO3-(aq) + 6H+(aq) In this reaction, some of the chloride
1A-Water/MSG: When shaken the water and MSG they mostly dissolve creating an orange gold color, the substance foams at the top from the vigorous shaking action yet still some MSG residue remains at the bottom of the test tube, it was unclear if the reason was because we did not mix it enough or rather we added too much MSG to the amount of water given. 1A-Alcahol/MSG: These two substances barely mix together leaving a transparent yellow tint to the alcohol as well as MSG that was unable to dissolve at the bottom of the test tube. We concluded that this residue was unable to be dissolved in this liquid because the amount of MSG remaining in the bottom of the test tube was around the same amount that was originally placed into the alcohol. 1B- Alcohol/Vegetable Oil: Created a foamy top layer, was semi unclear but as to the best of my observations the alcohol nearly completely dissolved the oil, leaving a foggy appearance to the once clear
Also, the more stable the free radical that is left behind, the weaker its C-H bond strength will be. The difference between the bromine and chlorine product ratios can be partially explained by the Hammond postulate, which states that species with similar energy levels also have more similar structures and react more quickly and less selectively. In the experiment, five different hydrocarbons were tested to measure the rate of reaction with the addition of bromine. Two trials were done, one with the test tubes containing the hydrocarbons and added bromine sitting directly under a lamp, and another with the test tubes in a closed, dark space. Both trials contained a
While hydrogen bonds have a uniquely high surface tension, van der Waals forces have a relatively weak attraction, which causes low surface tension. According to an author of Chem Guide, Jim Clark, in van der Waals forces, “the electrons are mobile, and at any one instant they might find themselves towards one end of the molecule, making that end slightly positive” (2000). In other words, oil is NOT a polar molecule like water, which causes the molecules to not stick to each other as well. The reason tension would occur is because the
Diffusion can only occur across a membrane if there is a concentration gradient and the membrane is passable. If neither one is present, diffusion won’t occur. The size of the tiny pores in a membrane, among other things, decides which particles can diffuse across the membrane. The process of a solute moving through a semipermeable membrane is known as dialysis. Osmosis is a specialized case of diffusion that involves the passive transport of water.
2011). KMnO4 cannot be used as a primary standard; this is because it is not stable in the presence of air. It oxidizes sporadically to MnO2. For this reason, the primary standard used is sodium oxalate, Na2C2O4. The standardization of of KMnO4 solution with Na2C2O4 is as follows: Oxidation: Na2C2O4→2Na++2CO2+2e- Reduction: KMnO4+8H++5e-→K++Mn+2+4H2O And the overall balanced equation: 16H++5Na2C2O4+ 2KMnO4→10Na++2CO2 These reactions are thermodynamically spontaneous, but the final one is susceptible to a side reaction and it is naturally very kinetically slow (Blandamer et al.
The concentration of a solution is the amount of solute that is dissolved into each unit of solvent. In this lab, water (H2O) will be the solvent and sugar/sucrose (C12H22O11). When the density of the solute is greater than the density of the solvent, the density is directly proportional to the concentration of the solute. The relative density of the solute to the solvent can be observed by placing some solute into the solvent without mixing. If the solute floats, then the density of the solvent is greater than the density of the solute.
The result proved: Contract to the hypothesis, at pH 12, activity of enzyme Catecholase and the rate of reaction decreased. Introduction pH is a measure of the concentration of hydrogen H+ in solution so the higher concentration hydrogen ion, the lower pH. pH is one of the most important factors affect to human body. pH was divided three parts on pH scale from pH 0 to pH 14: at pH 7, solutions are neutral. pH > 7 is alkalinity environment that will bind hydrogen ion, and pH < 7 is acidic environment that will donate hydrogen ion.
| Investigating Osmosis Through Living Membranes | Introduction: Diffusion is the tendency of molecules or ions to move from an area where they are in higher concentration to an area where they are in lower concentration, that is, down or along their concentration gradient (Marieb 2013). Osmosis is a special case of diffusion defined as the diffusion of a solvent, such as water, through a selectively permeable membrane (Marieb 2013). Osmosis occurs whenever the water concentration differs on the two sides of a membrane. Take a U-shaped container filled with a solution and separate the container into left and right compartments by a permeable membrane. Normally, net diffusion of both solute and water occurs until the concentration of water (and solute) is the same on both sides of the membrane (equilibrium).