Objective To determine of heats from three exothermic reactions and investigate the Hess Law Summary Based on this experiment, we have study three related exothermic reactions involving sodium hydroxide. The first reaction (Part A), solid sodium hydroxide will dissociate into water. The heat produce by this reaction (∆H1) and this called as the heat of solution of solid NaOH. From the experiment we have managed to determined that ∆H1 = -41.84 KJ/mol In the second reaction (Part B), an aqueous solution of NaOH is allowed to react with an aqueous solution of HCl. This is a neutralization reaction between a strong acid and strong base.
When potassium nitrate is placed in water the slightly positive hydrogen’s in the water molecule are attracted to the nitrate ions and the potassium ions are attracted to the slightly negative oxygen. Figure 1 shows how sodium chloride would bond when placed in water. Figure 1 Sodium chloride dissolved in water (Adams, R. et al, 2011) The solubility of a solute in a solvent is affected largely by the temperature. A solubility curve (as seen in Figure 2)
(4 points) q = m × c × Δt Given: q=? m = 34.720g c = 4.18 j/(g x °C) Δt = 41.6°C - 25.2°C = 16.4°C q = (34.720g) (4.18 j/(g x °C) (16.4°C) q = 2380.13j You are trying to figure out the energy change of the water which is the surroundings in the lab. To do that you must take the mass of the metal, which for me was Aluminum, and multiply it by the heat capacity of the water, which was given, then multiply that by the change in temperature, which is the final temperature of the mixture
The equation for the reaction is known as: Metal + cold water [pic]hydrogen(H2) + metal hydroxide (MeOH) The reaction is very exothermic and had the tendency to allow the hydrogen to ignite a fire. Sulfuric acid is a very strong dehydrogenation agent which allows it to be a danger to people. We had tested this on sugar instead of an actual human being. The chemical reaction is very exothermic and causes the intense dehydration of the sugar. The Sulfuric acid is a catalyst for the reaction.
At the other electrode (cathode), hydrogen gas is liberated at the surface through the reduction of hydrogen ions in the aqueous sulfuric acid solution. The reaction is: 2 H+(aq) + 2 electrons -> H2(g) This experiment is based on the mass loss of the copper anode, but it is also possible to collect the hydrogen gas that is evolved and use it to calculate Avogadro's number. Materials * Direct current source (battery or power supply) * Insulated wires and possibly alligator clips to connect the cells * 2 Electrodes (e.g., strips of copper, nickel, zinc, or iron) * 250-ml beaker of 0.5 M H2SO4 (sulfuric acid) * Water * Alcohol (e.g., methanol or isopropyl alcohol) * Small beaker of 6 M HNO3 (nitric acid) * Ammeter or multimeter * Stopwatch * Analytical balance capable of measuring to nearest 0.0001 gram Procedure Obtain two copper electrodes. Clean the electrode to be used as the anode by immersing it in 6 M HNO3 in a fume
The following steps were performed to create the ionic reaction. 2 drops of Sodium Phosphate, Na3PO4?12H2O solution were placed into the five vertical wells under column number 1. Next, 2 drops of Sodium Iodide, Nal solution were placed into the five vertical wells under 2. Next, 2 drops of Sodium Sulfate, Na2SO4 solution into five vertical wells under 3. Next, 2 drops of Sodium Chloride, NaCl solution were placed into the five vertical wells under 4.
So, qwater = qmetal Using the formula qmetal = m × c × ΔT, calculate the specific heat of the metal. Use the data from your experiment for the metal in your calculation. Part II: Calculate the energy change (q) of the surroundings (water) using the enthalpy equation qwater = m × c × ΔT. We can assume that the specific heat capacity of water is 4.18 J / (g × °C) and the density of water is 1.00 g/mL. Show ALL your work.
It is not combustible, but it speeds up the combustion of other substances because it is an oxidizing agent. It can react with combustible materials and emit toxic fumes. It is used in paint and ink pigments, as a wood preservative, or a corrosive inhibitor. It is a carcinogen to humans. Product A- Silver Chromate(s)~Ag2CrO4 Silver Chromate is a reddish-brown crystalline substance.
Thermal decomposition of carbonates Introduction: Carbonates decompose when they are heated, producing calcium oxide and carbon dioxide. Carbon dioxide can be detected using lime water. Calcium carbonate calcium oxide + carbon dioxide CaCO3 CaO + CO2 Other metal carbonates decompose in the same way. Here are the equations for the thermal decomposition of copper carbonate: copper carbonate copper oxide + carbon dioxide CuCO3 CuO + CO2 Hypothesis: some metal carbonates decompose more easily than others when they are heated. Aim: The times taken for a chemical reaction to take place metals high up in the reactivity series (such as calcium) have carbonates that take a lot of energy to decompose them.
The more active the metal the more basic it’s saturated hydroxide solution. The sulfate compounds of alkaline earth metals show decreasing solubilites as you go down a group. This characteristic is used as a means of separating and identifying metallic ions in a group. Carbonates are pretty insoluble. You will observe in this experiment some of the characteristics of the alkaline earth metals discussed here and will write balanced equations for all reactions.