Chapter 1, Problem 65b
Classify each of the following as a pure substance, a solution, or a heterogeneous mixture: (b) a 999 gold bar
Video transcript
Gold can be hammered into extremely thin sheets called gold leaf. An architect wants to cover a 30 m x 25 m ceiling with gold leaf that is twelve-millionths of a centimeter thick. The density of gold is 19.32 g/cm3, and gold costs $1654 per troy ounce (1 troy ounce = 31.1034768 g). How much will it cost the architect to buy the necessary gold?
A copper refinery produces a copper ingot weighing 70 kg. If the copper is drawn into wire whose diameter is 7.50 mm, how many meters of copper can be obtained from the ingot? The density of copper is 8.94 g/cm3. (Assume that the wire is a cylinder whose volume V = πr2h, where r is its radius and h is its height or length.)
Classify each of the following as a pure substance, a solution, or a heterogeneous mixture: (c) stainless steel.
(a) Which is more likely to eventually be shown to be incorrect: an hypothesis or a theory?
(b) A(n) _________ reliably predicts the behavior of matter, while a(n) _________ provides an explanation for that behavior.