Lab_1 - UOIT Chem 1800 W10 Exp 1-3.5 14 Once the solution is prepared stopper it and have the teaching assistant check your work The stopper needs

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UOIT Chem. 1800, W10: Exp. 1-3.5 48 14. Once the solution is prepared, stopper it and have the teaching assistant check your work. The stopper needs to fit snugly but should not be put in with excessive force. To do so, risks injury or jamming the stopper in the neck of the flask. 15. Invert the flask 20 - 25 times (while holding the stopper in place with your hand) to ensure thorough mixing.
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UOIT Chem. 1800, W10: Exp. 1-3.5 49 Experiment 1 - Lab Safety and Orientation Name: ____________________________ Student Number ____________________________ Day ____________________________ Time: ____________________________ TA Name ____________________________
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UOIT Chem. 1800, W10: Exp. 1-3.5 50
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UOIT Chem. 1800, W10: Exp. 1-3.5 51 Results and Questions Part I - Safety Orientation On a separate piece of paper answer the questions posed in the procedure. Include the completed laboratory template showing the locations of the safety equipment. Part III - Preparation of Standard Solution mass of 50 mL beaker + NaCl / g ____________________________________ mass of “empty” 50 mL beaker / g ____________________________________ mass of NaCl used / g ____________________________________ Final volume of solution / L ____________________________________ Checked by the TA (TA initials) ____________________________________ Calculate the concentration of the NaCl solution (in mol L -1 and with the correct number of significant digits).
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UOIT Chem. 1800, W10: Exp. 2-7.9 52 2. ATOMIC EMISSION SPECTRA Objectives 1) To observe the atomic emission spectra of two elements: mercury and hydrogen; 2) to calculate the Rydberg constant from the spectrum of the hydrogen atom; 3) to observe the spectra for several cations and note that cations give characteristic colours to flames; 4) to understand spectra are a valuable tool for identifying chemical species. Introduction In the late 19 th century Johann Balmer observed that when electric current was passed through hydrogen gas, the gas emitted light. When the gas was viewed through a spectroscope (see below), he observed discrete, bright lines against a dark background in the visible region of the electromagnetic spectrum. The discrete lines indicate that the hydrogen atom must exist in discrete energy levels. Otherwise, the emitted light would resemble a rainbow. He found he could relate the wavelengths ( ± ) of the lines to a constant, k, using the relationship: (2.1) 11 2 1 22 λ =− ± ² ³ ´ µ k n where ‘n’ was an integer > 2. The series of lines that he observed was called the Balmer series. Subsequently, series of lines were found in the ultraviolet (the Lyman series) and in the infrared (the Paschen, Brackett and Pfund series). These extra lines allowed the generalization of equation (2.1): (2.2) 1 1 2 2 2 ± ² ³ ´ µ R nn H where n 2 > n 1 . R H is known as the Rydberg constant and in this equation has units of reciprocal
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UOIT Chem. 1800, W10: Exp. 2-7.9 53 wavelength (commonly expressed in cm -1 ). The Rydberg constant was a purely empirical value and its literature value is 1.0973 x10 5 cm -1 . It had no theoretical basis until Bohr’s model of the hydrogen atom.
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This note was uploaded on 11/11/2010 for the course CHEMISTRY CHEM1800 taught by Professor Krista during the Winter '10 term at UOIT.

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Lab_1 - UOIT Chem 1800 W10 Exp 1-3.5 14 Once the solution is prepared stopper it and have the teaching assistant check your work The stopper needs

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