CHEM 103 Exam I - Atomic and Molecular Weights, Formulas, and Calculations, Exams of Chemistry

Download CHEM 103 Exam I - Atomic and Molecular Weights, Formulas, and Calculations and more Exams Chemistry in PDF only on Docsity! CHEM 103-Dr. Boyd October 4, 2002 Name Hour Exam I Lab Section 35 please print Lab TA Please copy and sign in the box below. I pledge on my honor that I have not given or received any unauthorized assistance on this examination. Signature: In all problems the method must be clearly shown. All numerical answers must be expressed using the correct number of significant figures. ************************* ̂ :*****#*********#*********=(!**^ #*########*** :|::|::M:;M: ###*#****#*#**:) Atomic and molecular weights: C... 12.011 H... 1.0079 O... 15.999 C3H5(OH)3 ... 92.095 ^^^^^^^^^sjc^^jfc^^^^^^^^^^^^^^^^^^^^^^^^^^^^^jf;^^^^^:^;^ 1. A. Write the formulae of B. Write the names of (4) i) ii) 2. Complete the following: i) ii) 1.234 x 10 10 (im=: 1.234 x 10 mm 1.234 x 10 10 Gm= 1.234 x 10 km 1.234 x 10 10 cm = 1.234 x 10 Mm (6) 3. Fill in the empty spaces in the following: (9) Number of Elections I Neutrons 4. As in class, define the following: Atomic weight (8) SCORE 2 3 4 Molarity Mole Solution 5. A sample of C3H5(OH)3 contains 2.0074 x 1022 molecules. (24) Calculate... A. the number of moles in the sample. Ans ___________ mol B. the percent hydrogen in the sample. Ans ___________ % C. the total number of atoms in the sample. Ans __________ atoms D. the percent of all the atoms which are hydrogen atoms. -2- Ans __________ %