Chem 101 Book Answers (Ch. 1)

Chem 101 Book Answers (Ch. 1) - Chapter 1 Early Experiments...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 1 Early Experiments 1-1 1. Distinguish between a qualitative observation and a quantitative observation. Give two examples of each. qualitative observation - An observation of an object, property, or phenomenon which not measured or quantified (involves no numbers). Examples: a) the rock is heavy; b) the water sample contains a small amount of benzene; c) upon burning magnesium in air, a solid white residue was formed. quantitative observation - one in which an object, property, or phenomenon or object is measured or quantified. Examples: a) the rock weighs 79.3 kg; b) the concentration of benzene in the water sample is 2.3 x 10 -7 mol/liter; c) upon burning 10.0 g of magnesium in air, 16.6 g of a solid white residue was formed. 3. Indicate whether each of the following represents a mixture of atoms, a mixture of molecules, or a mixture of atoms and molecules. Is each a mixture of elements, compounds, or elements and compounds? a) Each unit contains only a single atom, so it is a mixture of atoms and elements. b) Single spheres are atoms and elements, two bound spheres are molecules. Molecules of two blue spheres contain only one atom type, so they are elements. Molecules of blue and red spheres contain different atom types, so they are compounds. c) The single spheres are atoms and elements. The units containing a green and a yellow sphere are molecules or compounds. d) All units contain more than one sphere and are molecules. Some are composed of the same atom type (blue) and are elements, but others contain different atom types (yellow and green) and are compounds. 5. Classify each of the following as an element or compound: a) P 4 - element b) Fe - element c) C 3 H 6 O - compound d) SO 2 - compound e) O 3 - element 7. Classify each of the following as an atom or a molecule: a) P 4 - molecule b) Fe - atom c) C 3 H 6 O - molecule d) SO - molecule e) O 3 - molecule 9. Classify each of the following as an atom, molecule, anion or cation: a) NH 3 - molecule b) NH 4 1+ - cation c) N 3- - anion d) CH 3 COO 1- - anion e) Si - atom 11. Give the name of each of the following elements: a) Na - sodium b) Br - bromine c) Hg - mercury d) Fe - iron e) Ag - silver 13. Write the symbol for each of the following elements: a) copper - Cu b) lead - Pb c) strontium Sr d) silicon - Si e) tin - Sn 15. Determine the number of moles of atoms that are present in each of the following samples: a) 5.0 g K 5.0 g K × 1 mol K 39.1 g K = 0.13 mol K b) 17 g Mg 17 g Mg × 1 mol Mg 24.3 g Mg = 0.70 mol Mg c) 3.0 g C 3.0 g C × 1 mol C 12.0 g C = 0.25 mol C d) 2.2 kg Fe 2.2 kg Fe × 1000 g Fe 1 kg Fe × 1 mol Fe 55.85 g Fe = 39 mol Fe e) 14 mg Ag 14 mg Ag × 1 g Ag 1000 mg Ag × 1 mol Ag 108 Ag = 1.3 × 10 -4 mol 17. How many moles of molecules are in a 10.0-g sample of each of the following compounds? How many moles of atoms are in each sample?
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/30/2009 for the course CH Ch101 taught by Professor Bigham during the Fall '08 term at N.C. State.

Page1 / 4

Chem 101 Book Answers (Ch. 1) - Chapter 1 Early Experiments...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online