Hw2.3K-Int-Matter and Energy

Hw2.3K-Int-Matter and Energy - HW Set 2,3 - KEY GENERAL...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
HW Set 2,3 - KEY GENERAL CONCEPTS of MATTER and ENERGY CHM 1025 Hw2.3K-Int-Matter and Energy.wpd 1. a) copper - solid metal b) isopropyl alcohol - colorless liquid c) carbon dioxide - colorless gas d) carbon (diamond) - colorless, crystalline solid e) bromine - orange liquid f) sodium hydrogen carbonate (baking soda) - white, crystalline solid g) chlorine - yellow gas 2. a) tap water - liquid homogeneous mixture (solution) of water, dissolved minerals, perhaps chemical additives, dissolved gases -if sediment is present, then a heterogeneous mixture b) distilled water - pure substance (compound) gasoline - liquid homogeneous mixture of different hydrocarbon compounds and anti- knock additives d) bromine liquid and its vapor - pure element in two phases e) cube of sugar - pure compound (sucrose) sugar solution - liquid homogeneous mixture of the compounds sugar and water (presumably) g) sugar solution with sugar crystals on the bottom - heterogeneous mixture of solid sugar and liquid solution of water and sugar h) Bufferin tablet - solid particles of different compounds (aspirin, buffering agents, binders) that are compressed to form a tablet i) nitrogen gas - pure substance (element) j) brass - homogeneous mixture (one solid phase) of the metallic elements copper(67%) and zinc(33%) called an "alloy" k) partially molten iron - pure element in two phases (solid and liquid) l) iodized salt - two compounds, sodium chloride and a trace of sodium iodide m) ink, containing a soluble dye and suspension of fine particles of carbon - heterogeneous mixture of ink solution (liquid solvent and dyes) and solid particles of carbon n) battery fluid - of the compounds water, sulfuric acid, and lead salts o) 24 karat gold - pure metallic element p) 14 karat gold - solid homogeneous mixture of gold (58%) and other metals to increase hardness q) air - homogeneous mixture (a solution) of oxygen, nitrogen, some carbon dioxide, water vapor, and other elements and compounds 3. Total mass of the solution = 10.0 g + 300. g 310. g 2 % salt = 10.0 g x 100 = 3.23 % % H O = 300. g x 100 = 96.8 % Note that a solution is by definition, a homogeneous mixture, and its component proportions may be varied. A pure compound, on the other hand, is also homogeneous, but its elemental proportions are fixed. 23 4. a) Mass oxygen Mass Al O - Mass Al 7.99 g 4.23 g 3.76 g oxygen % Al = 4.23 g x 100 = 52.9 % % O = 3.76 g x 100 = 47.1 % 7.99 g
Background image of page 1

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

View Full DocumentRight Arrow Icon
2 4. continued b) 1st Experiment Mass Cl consumed = Mass NaCl - Mass Na 2.54 g 1.00 g 1.54 g Cl % Cl = 1.54 g x 100 = 60.6 % % Na = x 100 = 39.4 % 2.54 g 2nd Experiment Mass Na consumed Mass Cl 1.56 g 0.65 g Na % Cl = 100 = 0.65 g 39 % 1.65 g Both products analyze for the same percent-by-mass elemental composition, consistent the Law of Definite Proportions for any pure compound. c) 0.625 g C x 100. g sucrose x 6.5 g H 0.096 g H 42.1 g C 100. g sucrose 0.625 g C x 51.40 g O 0.763 g O 22 d) 10.0 g Si x 100. g SiO 21.4 g SiO 46.7 g Si 5. a) Gold is obtained from river sand by panning. Physical process: The element gold
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/16/2011 for the course CHM 1025 taught by Professor J during the Summer '09 term at Santa Fe College.

Page1 / 6

Hw2.3K-Int-Matter and Energy - HW Set 2,3 - KEY GENERAL...

This preview shows document pages 1 - 3. Sign up to view the full document.

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