Introduction Heat is the form of energy, thermal energy, which flows between two substances due to their difference in temperature.1 The measurement of heat flow is called Calorimetry and the apparatus used to measure the heat flow (temperature change) for a reacting system is called a calorimeter. The calorimeter is well-insulated device that help to minimize the heat exchange between the system being observed and its surroundings. In this experiment, simple calorimeter, coffer cup calorimeter containing Styrofoam cups is used. Calorimeter contains a thermometer and a stirrer.3 Thermometer is typically inserted in the calorimeter to measure the change in the temperature that results from the reaction. Stirrer is used to keep the contents …show more content…
ΔH= q Specific heat is the amount of heat needed to raise the temperature of one gram of a substance by 1 C (or 1 K).1 Specific heat of water is equal to 4.18 J/ g℃.1 In order to determine the specific heat capacity of metal, it is necessary to know mass and change in temperature, specific heat of water, also change in temperature and mass of metal used: q_(H_2 O)=〖S.H.〗_(H_2 O) × m_(H_2 O) × ∆t_(H_2 O)= -〖S.H.〗_M × m_M × …show more content…
Firstly, 39.15 g of water was used and molar mass of metal was determined to be 61.43 g/mol, then 50.88 g of water was used and molar mass of metal was determined to be 59.24 g/mol. If the amount of water in the calorimeter varies, and thus the heat capacity of the water would vary. Firstly, specific heat capacity of metal was determined, which depends on heat of the water mass of the water and mass of the solid, then molar mass using: MM= 25/(S.H.(J/(g℃)) ) In the Part B of the experiment q_(H_2 O) for the reaction was find to be 2279.5 joules, ∆H for the reaction = -2279.5 joules, ∆Hsolution = -455.9 joules/g. This solution reaction is exothermic; because temperature was increased meaning heat was released. In the last part of the experiment, neutralization reaction was investigated. NaOH(aq) + HCl(aq) NaCl(aq) + H2O(l) Enthalpy change for neutralization reaction between HCl and NaOH were calculated to be -51kJ. For reactions involving strong acids and alkalis, like HCl and NaOH, the values are always very closely similar, with values between -57 and -58 kJ.2 The actual value of enthalpy change of neutralization reaction is equal to -57.9 kJ.2 The reason for dissimilarity of results could be loss of heat during the transferring of the NaOH to the HCl. Since, temperature was increased, the reaction is exothermic, heat was
A hot plate was placed under the ring stand. 50 mL of 3.0 M NaOH in a 250 mL beaker and a stir bar was placed in the beaker. The beaker with NaOH was placed on the hot plate and 3.75 grams of NaAlO2*5H2O was placed in the beaker. The temperature probe was placed in the beaker with the solution, not touching the bottom of the beaker. The solution was heated and stirred till the solution dissolved.
After the water temperature began to stabilize, the highest constant temperature was recorded. This data was used to calculate the calorimeter constant. This enter procedure was repeated to calculate another calorimeter constant in order to find the average of both answers. After that value was calculated, a 600 mL beaker was filled with 300 mL of water and heated till it started boiling. An unknown metal located on the instructor's bench was obtained and the mass was calculated.
Thermochemistry What is the specific heat of platinum if 1092 J of heat were released into a calorimeter when it was cooled by 65.2 C A 185 g sample of copper at 98.0 C was added to 102 g of water at 20.0 C in a calorimeter. The final temperature of the copper-water mixture was 31.2C. Calculate the specific heat of copper using this data. How much heat in kJ is required to raise the temperature of 250.0 g of Hg 52.0 C? the heat capacity of Hg is 0.14 J/gC.
1. A number of different items were measured in this lab. For each of the following items, what did you find most challenging in making the measurement and how did that challenge affect the accuracy of the measurement? a) Length of the table b) Height of your partner c) Thickness of your finger
It is being changed by a ball in a oven to make it hot or a ball in the freezer to make it cold. Temperature can be measured by
Al(s) wire was placed in the solution from the last step and 5 drops of HCl along with a stir bar was added to the beaker and this was stirred on the hot plate. Cu(s) precipitate formed on the wire and the solution turned from clear to cloudy until it eventually become a brownish red color. When the reaction was complete the Al(s) wire was scraped with the stirring rod to get off any residual Copper product. All of the reactions except for reaction 3 were exothermic. This is because each reaction gave
Introduction The purpose of this lab was to compare galvanizing and creating brass with pennies using weight change, mass change and observations. The independent variables are the types of pennies used. The dependent variables are the characteristics, change in pennies, and mass of the pennies.
In addition, phenolphthalein was added as an indicator. The aliquots were titrated against sodium hydroxide (NaOH) solution until end point was reached, after which volume of NaOH consumed was recorded. The value of the rate constant, k, obtained was 0.0002 s-1. The experiment was then repeated with 40/60 V/V isopropanol/water mixture and a larger value of k = 0.0007 s-1 was obtained. We concluded that the rate of hydrolysis of (CH3)3CCl is directly proportional to water content in the solvent mixture.
I. Purpose: To experimentally determine the mass and the mole content of a measured sample. II. Materials: The materials used in this experiment a 50-mL beaker, 12 samples, a balance and paper towels. III.
Observations: 1. The first step had to be repeated due to not following proper instructions. I did not grease the screw, so as I was shaking the mixture, solids were forming around the screwpart of the separatory funnel. 2. When adding 5.0 mL of NaOH to the unknown mixture and shaking it for about 30 seconds, layers had formed.
Then the scientist will observe the different rates of reaction with temperature. The Boltzmann distribution of law, indicates that high temperature makes molecules gain high energy contents (pubs.acs.org/doi/abs/10.1021/ja). In order to measure the reaction rate, the scientists must use the same volume of water at three different starting temperatures: hot tap
Catalase and Temperature Introduction Background: Enzymes are catalysts which help reactions inside of organisms such as cells. Many different types of enzymes are used to catalyze different types of reactions. Enzymes are able to catalyze reactions that normally wouldn’t be possible under the specific circumstances in the cell such as the pressure or temperature of the cell. The way an enzyme works is it binds with the active site of a substrate and creates an enzyme substrate complex. The enzyme then breaks apart the bonds in a substrate and then leaves unchanged after the reaction.
Another way to calculate the enthalpy of neutralization is to assume the density of the solution to be equal to the density of water in order to assume the mass of the solution. 1.00 g 〖cm〗^(-3)×50 cm^3±0.96 %= 50.00 g ±0.96 % The heat released can then be calculated using the assumed mass. q=50.00 g±0.96 % ×4.18 J g^(-1)
A toaster oven is one of the most versatile kitchen appliances available today. They are considered to be great dual-purpose kitchen appliances because they function both as a toaster and as an oven. They can prepare anything from a simple piece of toast to a full-on meal. This versatility makes them a very popular addition to many household kitchens.
Calorimeter helped many generations to measure the quantity of heat using different types of devices; also they followed a specific procedure and equations to find out quantitative