6)Which of the following are true statements ?
a) The density of an substance is a chemical property
b) The thermal conductivity of a substance is a physical property
c) Saying argon is an inert gas describes a chemical property of this gas
d) Burning wood is an example of a chemical change
e) The melting temperature of an element is a physical property
7) A compound contains 70.8 percent silver. How many moles of silver does a 62.1 g sample contain ?
2007-09-15 06:40:32 · 4 answers · asked by matt b 1 in Science & Mathematics ➔ Chemistry
All statements are true except (a) density is a physical property. 1 mole of Ag would weigh approximately 107.87 g. Since the sample is 70.8% Ag then the 62.1 g sample would contain approximately 43.97 g of Ag. Dividing 43.97 by 107.87 gives you approximately .4076 moles of Ag. I hope your school lets you use calculators because those approximations are really difficult if you have to calculate them on paper. Hope I've helped. Thanks for the 2 points!
2007-09-15 07:55:17 · answer #1 · answered by Emissary 6 · 0⤊ 0⤋
6) B, C, D, E
7) .708 * 62.1 g sample = 43.9668 g silver
43.9668 g silver * (1 mol silver/107.9 g silver) = 0.407 mol silver (this takes into account significant figures)
2007-09-15 06:52:13 · answer #2 · answered by cablejumper17 2 · 0⤊ 0⤋
a) no -physical
b) yes
c) yes
d) yes -combustion
e) yes
2007-09-15 06:48:34 · answer #3 · answered by maussy 7 · 0⤊ 0⤋
6. D,E,B
7. not sure sorry :/
2007-09-15 06:44:47 · answer #4 · answered by Jammin EMmm 3 · 0⤊ 0⤋