Sodium Hydroxide + Hydrochloric Acid Sodium Chloride + Water NaOH(aq) + HClaq → NaCl(aq) + H2O(l) Variables Independent The independent variable of the experiment was the amount of sodium hydroxide that we added to the acid. To keep the variable controlled we would measure 1 ml of the sodium hydroxide and pouring that to the hydrochloric acid. Dependent The dependent variables of the experiment were the temperature and the pH number of the mixture. To control the pH and temperature use the electronic probe and data logger. Controlled The controlled variables of the experiment were: A.
Report Submitted: September 22, 2013 Title: Properties of Gases Purpose: To investigate some physical and chemical properties of gases. Procedure: Explored physical and chemical properties of gases and used these properties to identify the gases and when they were present 1. Hydrogen: B. Observation of placing Zinc into HCI was the appearance of gas bubbles rising to the surface 2. Oxygen: B. Reacts the same as hydrogen with gas bubbles rising to the surface.
The mass of the oxygen is resulted from the difference between the masses of product oxide and limiting reagent. In equation 1, the mass of limiting reagent magnesium is found. The mass of the oxide product is determined using equation 2. In equation 3, the amount of oxygen in magnesium oxide is found using the weights of the results found in equation 1 and 2. The mass of the oxygen in the oxide product will represent how much added weight was gained in the reaction.
Part B Was hydrogen present in the test tube? How could you tell? If your test did not confirm the presence of hydrogen, give a possible explanation. Hydrogen gas was produced through the reaction of hydrochloric acid, and zinc. This is provable by the reaction that occurred with the two gases hydrogen and oxygen.
Introduction High performance liquid chromatography (HPLC) is used to separate compounds in a sample, identify compounds and can even be used to deduce the relative amounts of different compounds in a mixture. HPLC works under the same principle as thin layer chromatography using both a stationary and mobile phase. The mobile phase carries the mixture across the stationary phase which is used to separate the compounds. Although in HPLC mobile phase is tailor made to suit the polarity of the analytes. The mobile phase used in this particular experiment was Methanol and 0.1M sodium dihydrogen phosphate at a ratio of 30:70 and a pH of 4.5, slightly acidic.
From these equilibrium concentrations, the equilibrium constant for the reaction can be determined. The purpose of this experiment is to determine the equilibrium constant for the following hydrolysis of an ester reaction: CH3COOCH2CH3 (aq) + H2O (l) CH3CH2OH (aq) + CH3COOH (aq) Ethyl Acetate Water Ethanol Acetic Acid (EtAc) (EtOH) (HAc) The equilibrium constant, Kc, for the reaction will have the following expression: Several reaction mixtures will be prepared with different initial amounts of ethyl
In our lab we use a more sophisticated one which included a lid on the cup with an inserted thermometer and a stirrer. Thermochemistry is the study of the heat released or absorbed as a result of chemical reactions. The measurement of the total energy of a thermodynamic reaction is called enthalpy (q). This is the basis for Hess’s law which states that if two reactions are combined to yield a third reaction, the sum of the first two is equal to the third. The energy change is the same whether the process occurs in one step or many.
Magnesium gives up two electrons to oxygen atoms to form this powdery product which is a form of synthesis reaction. Balanced chemical equation ---- 2 Mg (s) + O2 (g) → 2 MgO (s) Couple of changes should occur after the magnesium is burned and magnesium oxide is formed. The mass of the magnesium should increase after the process of burning and becoming magnesium oxide. The increase in mass is due to the fact that oxygen from the air has combined with the magnesium to make magnesium oxide and that will cause a combination between the mass of the oxygen and the mass of the magnesium that is used in the experiment.
The purpose of the experiment was to confirm the empirical formula of magnesium oxide. It was determined and confirmed that the empirical formula is MgO. In a combustion reaction, 0.0916g of magnesium was reacted with atmospheric oxygen to produce .1523g of oxide of magnesium. Cautionary measures were taken to convert magnesium nitride, a side-reaction, to oxide of magnesium using 10 drops of water. The difference between the mass of the compound and the mass of magnesium tells the mass of oxygen that participated in the reaction.
Molecular Weight by Dumas Method In your text (Chang, 10th Ed) : 5.4 The Ideal Gas Equation, especially the Density and Molar Mass of a Gaseous Substance subsections Purpose: The experimental determination of the molecular weight of a volatile liquid sample and the density of its vapor are used to illustrate the uses of the Ideal Gas Law. Background: The Ideal Gas Law is: PV = nRT (Eqn. 1) where P = pressure in atm, V = volume in L, T = temperature in K, and R = 0.082056 L atm/(mol K), the Gas Constant It describes, with good precision, the behavior of many real gases over a wide range of pressures and temperatures. Even when there is deviation from ideality, it is useful as a starting point in physical analysis Recalling that density is mass/volume, Eqn. 1 can be re-written to derive the equation for the density of a gas, assuming ideal behavior: n = P Now multiply both sides by MW: n(MW) = P (MW) V RT V RT n(MW) is # moles x grams/mol = grams = mass, m Therefore: m = (P)(MW) = d , density (mass/volume, in grams/ liter ) (Eqn.