Quarter II Part I: Stoichiometry

Sample Question I Elements from which two groups in the periodic table would most likely combine with each other to form an ionic compound? From: Virginia End-of-Course Assessments, 2001 Chemistry A1 and 2 B1 and 17 C16 and 17 D17 and 18

Sample Question II What is the approximate mass of one mole of CO 2 ? From: 2008 Virginia End-of-Course Assessments, Chemistry A24 g B44 g C28 g D56 g

Sample Question III A student calculated the molar mass of Ca(OH) 2 as follows: The answer he calculated is wrong. Which labeled step contains his mistake? A. Step 1 B. Step 2 C. Step 3 D. Step 4

Sample Question IV In chemical compounds, covalent bonds form when From: 2003 Virginia End-of-Course Assessments, Chemistry Athe electronegativity difference between two atoms is very large Belectrons are completely transferred between two metals Cpairs of electrons are shared between two nonmetal atoms Dtwo nonmetal ions are attracted to each other by opposite charges

Sample Question V If the diagram below was the correct representation for the Lewis structure of a molecule, then the X would be representative of the element From: 2003 Virginia End of Course Assessments, Chemistry AOxygen CNitrogen BFluorine DPotassium

The sample below contains approximately 9.03 x atoms of Carbon. The sample most likely contains… A. 1 mole of Carbon B. 1.5 moles of Carbon C. 1 molecule of Carbon D x molecules of C Sample Question VI

A student was asked to calculate for the approximate number of molecules that can be expected from a 40-gram sample of glucose. Her calculations are found below. Her teacher informed her that she made an error. Which labeled step contains the error? A. Step 1 B. Step 2 C. Step 3 D. Step 4 Sample Question VII

Sample Question VIII The structural formula of methane is shown below: From the elements making up the compound, this molecule is most likely… A. crystalline B. ionic C. covalent D. highly polar

Sample Question IX A compound has the empirical formula CH 2 O and a gram-formula mass of 60 grams per mole. What is the molecular formula of this compound? From: 2009 Aug NY Regents (Chemistry) A) CH 2 O B) C 2 H 4 O 2 C) C 3 H 8 O D) C 4 H 8 O 4

Sample Question No. X The mass of one atom of Potassium is... A) 1.54 x g B) 6.49 x g C) 3.15 x g D) 1.14 x g

Sample Question XI Which atom in the ground state has the most stable valence electron configuration? From: 2009 June NY Regents (Chemistry) A) K B) Si C) Sc D) Kr