B. How does the change in temperature affect the volume of the container? Get the Gizmo ready: Activity A: Boyle’s law Set the temperature (T) to 300 K. Check that the mass (m) is set to 0 kg. Question: How does pressure affect the volume of a gas? 1.
The study of specific heat falls under the category of Thermochemistry which is further divided into the category of Calorimetry. An instrument called a calorimeter is used to measure specific heat. A piece of metal is placed in a container of water. This is then boiled. The piece of metal is then taken out of the boiling water and placed in a calorimeter which contains room temperature water.
Therefore, according to Hess’s law, the heat of reaction of the one reaction should be equal to the sum of the heats of reaction for the other two. This concept is sometimes referred to as the additivity of heats of reaction. The primary objective of this experiment is to confirm this law. The reactions we will use in this experiment are: 18 - 1 Computer 18 You will use a Styrofoam cup in a beaker as a calorimeter, as shown in Figure 1. For purposes of this experiment, you may assume that the heat loss to the calorimeter and the surrounding air is negligible.
The concentration is measured in molarity. Molarity is the measure of moles of solute per liter of solution. The rate law helps one find solution's reaction order. If the reaction order is zero, the graphical representation is concentration vs. time, and the slope of the line is the negative rate constant. If the reaction is first order, its graphical representation is seen as ln[A] (natural log of concentration) vs. time, and the slope of its like is also the negative rate constant.
Data: Data Table 1 | | | Rubbing Alcohol Trial # | Boiling Point | Percent Error | 1 | 79.5 C | 3.52% | 2 | 84.0 C | 1.90% | 3 | 83.5 C | 1.30% | Data Table 2 | | | | Acetamide Trial # | Melting Point | Freezing Point | Percent Error (Melting Point) | 1 | 79.5 C | 57.5 C | 3.50% | 2 | 80.5 C | 59.5 C | 0.60% | 3 | 78.0 C | 61.0 C | 3.70% | Observations: It was observed that thermometer placement could affect the readings in the water bath. I ended up holding the test tube assembly to where the bottom of the test tube was not touching the bottom of the beaker to ensure better readings. Also, when substances recrystallize, I am not sure whether to take a reading when the substance has full crystallized or begun to so results could be fairly inaccurate. Questions: A. Why is it useful
Lab 4: Determination of Percent by Mass of the Composition in a Mixture by Gravimetric Analysis Introduction Thermal gravimetric analysis is used to determine the percent by mass is used to determine the percent by mass of a component in a mixture. When a mixture is heated to an appropriately high temperature, one component in the mixture decomposes to form a gaseous compound. The mass of this particular component is related to the mass of the gaseous compound. In this experiment, the percent by mass of sodium hydrogen carbonate (NaHCO3) and potassium chloride (KCl) in a mixture will be determined. Experimental First, we weighed 2 samples, each has 1 gram of NaHCO3-KCl mixture Second, we put the samples in 2 crucibles (A and B) and weighed them.
Question: Find a method to find the specific heat capacity of an unknown object. Hypothesis: Using the equation q=mc∆T, the heat capacity of the unknown object can be determined. Assuming heat loss by water = heat gained by the object, we can use two simultaneous equations to solve for the c value of the object. Variables: Controlled – time for water to cool, mass of metal, volume of water Dependent – change in temperature Materials: • Hot plate • The unknown object • Thermometer • Mass balance • Calorimeter • Water • Beaker Procedure: 1. Carefully measure 200 mL of water for the beaker and the calorimeter.
Lesson 13.6 Changes of physical state: * necessary to draw a temperature-energy graph to see the change in temperature with a constant application of heat Heat of fusion - the amount of heat required to melt 1.00 g of substance. substance changing from a solid to a liquid. Heat of vaporization - the amount of heat required to vaporize 1.00 g of a substance. substance changing from a liquid to a gas. heats of vaporization and condensation are equal.
e. is one-half. 3. The gas phase reaction A + B C has a reaction rate which is experimentally observed to follow the relationship rate = k[A]2[B]. Which one of the following would affect the value of the specific rate constant, k? a. decreasing the temperature b. changing the concentration of A c. changing the concentration of B d. changing the concentration of C e. letting the reaction go on for a long time 4.
Raoult’s Law was used in this experiment because it describes the vapor pressure that takes place in the experiment. The law states “The vapor pressure of a solution of a non-volatile solute is equal to the vapor pressure of the pure solvent at that temperature multiplied by its mole fraction.” (Clark) This means that the vapor pressure of a solution depends on the vapor pressure of the solutes making up the solvent. Dalton’s Law says that the total vapor pressure of a solution is equal to all of the individual vapor pressures that make up the solution. (Blauch) This law was also used in the lab due to the binary mixture of cyclohexane and toluene. Experimental Section – * Setup fractional distillation equipment * Gathered 7mLof stock mixture * Added four boiling stones