Atomic Theory and Structure The Mole and Atomic Mass: Definitions, conversions, and Avogadro's number by Anthony Carpi, Ph.D. Reading Quiz Teach with this 1. One "mole" in chemistry represents the number: 2.06 x 1023 6.02 x 1023 0.62 x 1023 10.23 x 62 2. The International Committee for Weights and Measures (ICWM) defines one mole as the number of atoms in exactly: 12 grams of any metal 1 gram of any metal 1 gram of carbon-12 (12C) 12 grams of carbon-12 (12C) 3. Since 12C’s molar mass is 12 grams, 48 grams of 12C atoms would be equal to ____ moles. 2 4 6 The answer cannot be determined 4. Avogadro’s number acts as the conversion factor for converting between the number of moles in a sample and the number of molecules in the sample. true false 5. If there are 0.20 moles in 8.9 grams of CO2, what is the number of CO2 molecules? Use this equation to find the answer: Moles in sample (mol) x Avogadro's number (6.022 x 1023) = Number of sample molecules 0.20 x 1023 1.2 x 1023 8.9 x 1023 20 x 1023 6. Molar mass is a numerical value that represents ______. the mass of a substance divided by the amount of that substance the mass of a substance the amount of a substance the number of atoms in a molecule 7. An element’s molar mass and atomic weight are always equal. false true 8. The element Vanadium has two stable isotopes 50V and 51V. The mass and abundance of these isotopes are 50V = 49.9472 amu and .0025 abundance and 51V = 50.9440 amu and .9975 abundance. With this information, what is the atomic weight of Vanadium? 23 49.947 50.944 50.9415 9. The atomic weight of Hydrogen is 1.0079 amu and the atomic weight of Oxygen is 15.999 amu. Using this information, what is the molecular weight of a molecule of water, H2O? 2.016 amu 17.007 amu 18.015 amu Unknown 10. The definition of a mole is not open to scientific debate because it is unchanging. false true Score Quiz
