CHEM 103 LAB EXAM (PORTAGE LEARNING) WITH COMPLETE SOLUTIONS

CHEM 103 LAB EXAM (PORTAGE LEARNING) WITH COMPLETE SOLUTIONS Question 1 10 / 10 pts Scientific Calculator Answer the following five questions: 1. What is the wide-mouthed glass container shown below? 2. Why is glass so often used as a material for lab containers? 3. What is the metal device used to hold hot containers? 4. What is the weighing dish used for solids? 5. What device is used to smother small fires? Your Answer: 1. Beaker 2. Glass will withstand almost anything, like acids 3. tongs 4. watch glass 5. fire blanket 1. beaker 2. Glass is so often used as a material for lab containers because it is unreactive with most lab chemicals. 3. The metal device used to hold hot containers is tongs. 4. The weighing dish used for solids is a watch glass. 5. A fire blanket is used to smother small fires Question 2 8 / 10 pts This study source was downloaded by from CourseH on :59:16 GMT -05:00 CERTIFIED Scientific Calculator Answer the following five questions: 1. Which is the slowest of the lab balances? 2. The mass of the graduated cylinder on analytical balance #1 was ? grams. 3. The mass of the graduated cylinder on top loader balance #1 was ? grams. 4. The mass of the metal cylinder on analytical balance #1 was ? grams. 5. The mass of the cell phone on top loader balance #2 was ? grams. Your Answer: 1. 2 pan balance 2. 47.6204g 3. 47.62g 4. 21.5953g 5. 92.98g 1. The slowest of the lab balances is the triple-beam balance. 2. The mass of the graduated cylinder on analytical balance #1 was 47.6204 grams. 3. The mass of the graduated cylinder on top loader balance #1 was 47.62 grams. 4. The mass of the metal cylinder on analytical balance #1 was 21.5953 grams. 5. The mass of the cell phone on top loader balance #2 was 92.98 grams. Question 3 10 / 10 pts Scientific Calculator Answer the following three questions: 1. Which of the devices was determined to have the smallest % error in volume delivered in lab 1? 2. What was the calculated volume for the 100 ml graduated cylinder in the volume measurement experiment? This study source was downloaded by from CourseH on :59:16 GMT -05:00 3. Water at 23.9oC has a density of 0.99732 g/ml. A 10.2 ml sample of water at 23.9oC, delivered from a graduated cylinder had a mass of 9.8851 grams as measured on an analytical balance. (1) Show the calculation of the actual volume as determined from this mass. (2) Show the calculation of the % error in volume delivered for this graduated cylinder. % error = (│delivered value - calculated value│/delivered value) x 100 Your Answer: 1. pipet 2. 10.40ml 3. measured volume= 9.8851g/0.99732=9.91ml % error = (10.2-9.91)/10.2 x100 =3% 1. The device determined to have the smallest % error in volume delivered in the volume measurement experiment was the pipet. 2. The calculated volume for the 100 ml graduated cylinder in the volume measurement experiment was 10.40 ml. 3. (1) Actual volume = M / D = 9.8851 / 0.99732 = 9.91 ml (2) % error = (│10.2 – 9.91│/ 10.2) x 100 = 2.84% error This study source was downloaded by from CourseH on 08-2