Chapter Assessment Answer Key Chemistry: Matter and Change T167 4 CHAPTER ASSESSMENT Date alpha radiation Dalton’s atomic theory radiation radioactivity Chapter Assessment particles involved in a reaction. Chemistry: Matter and Change • Chapter 4 nucleus. A nuclear equation shows the atomic number and mass number of the 19 Both concern changes in atoms. A nuclear reaction involves a change in an atom’s 15. nuclear reaction, nuclear equation atom. in the nucleus of a given atom.
Nest one Styrofoam cup in another 11. Obtain an exact mass of tap water (45-50g) to serve as cold water 12. Put a magnetic stirrer in the bottom of the calorimeter 13. Secure temperature probe to a ring stand 14. Place temperature probe through hole in cardboard lid and position probe about 1cm above bottom of calorimeter 15.
(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
0.00079 moles EDTA4- c. 0.00079 moles ZnI2 d. 0.0517 grams of ZnI2 are in the sample e. 0.0517/0.237= 21.8% f. Error Is 6.34% Lab Report: Part 1: In this lab we used the following supplies: * Zinc Iodide * Na2H2EDTA(s) * Calmagite indicator solution * pH 10 buffer solution * 6M Acetic Acid * Unknown Zinc Compound The main purpose for this part of the lab was to determine the amount of zinc ion in a sample of ZnI2 by titration. The two types of zinc: * Zinc iodide made by zinc and iodine * Commercially purchased zinc iodide (the
Chlorine gas can be produced in the laboratory by adding concentrated hydrochloric acid to manganese(IV) oxide in the following reaction: MnO2(s) + 4HCl(aq) ( MnCl2(aq) + 2H2O(l) + Cl2(g) a. Calculate the mass of MnO2 needed to produce 25.0 g Of Cl2 ans: 30.7 g MnO2 b. What mass of MnCl2 is produced when 0.091 g of C12 is generated? ans: 0.16 g MnCl2 1. How many moles of ammonium sulfate can be made from the reaction of 30.0 mol of NH3 with H2SO4 according to the following equation: ans.
Objective The purpose of this experiment was to become familiar with the ability to reproduce an experiment several times. Experimental Materials 1 x Magnetic Stirring Bar (yellow) 2 x 100 mL Flask 8 x 50 mL Erlenmeyer flask Magnetic Hotplate Glass Stirring rod Distilled water Pipet (with Pump handle) Starch 0.20M Ammonium Persulfate (NH4)2S2O8 0.20M Ammonium Sulfate (NH4)2S2O4 0.20M Potassium Nitrate (KNO3) 0.20M Potassium Iodide (KI) 1.2 x 10-2M Sodium Thiosulfate (Na2S2O3) Experimental Method 1. All materials were obtained from the classroom. 2. The flasks were thoroughly cleaned with distilled water.
UNCW Honors Chemistry Lab #1- Laboratory Safety and Boiling Water Date Started: 8/26/11__________________ Date Completed __________________ Purpose: To determine the temperature at which water boils. To learn how boiling and melting are physical changes. Background Information/Observations: 1) Explain the most common scenario when you observe water boiling. 2) Explain how you could change the rate at which water boils. 3) Explain how you could change the temperature at which water boils.
* Tape measure, 3 m * Mercury thermometer * Tuning fork, 384 Hz * Marker pencil * Block of wood C. Data Table 1: Tuning fork frequency (Hz) | Length, L Water level to top of the tube (m) | D= diameter of tube (m) | Wavelength=4(L+0.3d)(m) | Room temperature (degrees C) | 384 | 0.218 | 0.020 | 0.896 | 24 | D. Calculations A. In order to find the wavelength: Wavelength=4(L+0.3d) Next, plug in the values from Data Table 1 in to find the sound wavelength: Wavelength=4(0.218m +0.3*0.020m) Wavelength=4(0.218m+0.006m) Wavelength=4(0.224m) Wavelength=0.896 m In order to find the experimental value of v (speed of sound): V=f*wavelength (The value of f [frequency of the tuning fork] was found written on the side of the tuning fork.) v=384 Hz*.896m v=344.064 m/s In order to find actual speed of sound: (where Tc=room temperature in degrees Celsius) V speed of sound=331.4+0.6Tc m/s V speed of sound=331.4+0.6(24) m/s V speed of sound=345.8 m/s B. % error was found by using the following calculations: % error=(experimental value-theoretical value*100)/theoretical value % error= (344.064 m/s-345.8 m/s*100)/345.8 m/s % error=+-0.502% C. Consider the length of your resonance tube, what is the lowest frequency tuning fork you could use for this exercise? Show your calculations.
Aim To compare the reactivity of various metals by observing their reaction with hydrochloric acid Hypothesis That the all the metals will produce foam and a pop. Variables Independent – Magnesium, Aluminium, Zinc, Copper Dependent – Detergent, Hydrochloric Acid Controlled – Size of the metals, amount of detergent and hydrochloric acid Materials 2 M hydrochloric acid Detergent 10 x test tubes and test tube rack and 5 rubber stoppers 0.5 cm pieces of magnesium, aluminium, zinc and copper 2 cm pieces of magnesium, aluminium, zinc and copper Steel wool Ruler Timer Bench mat Matches and birthday candle Marking pen Safety Remember to wear safety glasses and protective gloves when you do this experiment. 2 M HCl is corrosive. Wash with plenty of water should you get any on your skin or in your eyes. Method Part 1 1 Clean the surface of the 0.5cm piece of magnesium with a piece of steel wool 2 Place the magnesium into a test tube 3 Add three drops of detergent to the test tube 4 Add 2 cm of hydrochloric acid to the test tube.
CHEMISTRY Name _____________________________ Lab - Molar Volume of a gas lAB 12 OBJECTIVE OF THE LAB: The purpose of this lab is to determine the molar volume of a sample of Hydrogen gas that is created through the reaction of Magnesium and Hydrochloric Acid. The concept of molar volume is that 1 mole of a gas occupies 22.4 liters at STP. Unfortunately the conditions of the lab are not at STP. You will have to use gas law formulas to calculate the volume that one mole of this gas would occupy at STP. In addition, since this lab is being done over water, and water will evaporate at any temperature, the vapor pressure of water must be determined.