(a) Read the following description of the element zinc and indicate which are physical properties and which are chemical properties.
Zinc melts at 420 °C. When zinc granules are added to dilute sulfuric acid, hydrogen is given off and the metal dissolves. Zinc has a hardness on the Mohs scale of 2.5 and a density of 7.13g/cm3 at 25 °C. It reacts slowly with oxygen gas at elevated temperatures to form zinc oxide, ZnO.
(b) Which properties of zinc can you describe from the photo? Are these physical or chemical properties?
Wednesday, January 27, 2016 Moles, Conversions, Avogadros Number Chapter 3 Introduction to the Mole Concept - The periodic table shows the wighted average mass of an element, which means that the relative abundance of isotopes are taken into consideration • H —> 1.008 amu • C —> 12.01 amu • Fe —> 55.847 amu - How do we measure these • Common lab balances measure in grams, not amu - Remember, 1 amu = 1.66053873 x 10^-27 Avogadro’s Number - H —> 1.008 amu • 1 amu = 1.6605 x 10^-27 kg - Diatomic molecules will be 2 x 6.022x10^23 • Which are not atoms anymore but molecules Mole (mol) - Mol: Amount of substance that contains as many basic particles as there are atoms in exactly 12 g of C-12 •