2010F_chem_125_exam_1--44gt60xx3aNswers-e-e-ee-e-e

2010F_chem_125_exam_1--44gt60xx3aNswers-e-e-ee-e-e - Chem...

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

View Full Document Right Arrow Icon
Chem 125 Exam #1 Fall 2010 Ellis PART A. (4 Points each) 1. 5A + 3B 6C + 8D. How many moles of A are required make 1.63x10 -3 moles of D? a. 1.63x10 -3 b. 1.00x10 -3 c. 9.31x10 -4 d. 2.61x10 -3 e. 1.02x10 -3 2. A sheet of Gold (like a piece of paper; only it's gold) 11 inches by 11 inches has a mass of 0.0215 g. What is the average thickness of the sheet of gold? Possibly useful information: The density of gold is 19.3 g/cm 3 and 1 in = 2.54 cm. a. 1.43 x10 -6 cm b. 1.60x10 -5 cm c. 3.99 x10 -5 cm d. < 10 -6 cm e. > 10 -4 cm 3. What is the correct formula of Iron (II) carbonate? a. FeC 2 b. Fe 2 C c. FeCO 3 d. Fe(CO 3 ) 2 e. none of the above 4. What is the approximate molar mass of magnesium nitrate? a. 101 g/mol b. 141 g/mol c. 70. g/mol d. 86 g/mol e. 148 g/mol 5. What is the oxidation state assigned to nitrogen in NHF 2 ? a. 0 b. +2 c. -1 d. -3 e. +1 3 3 1.63 10 5 1.02 10 mol B 1 8 x mol D mol A x x mol D - - = 6 2 2 3 . 0.0215 1.43 10 19.3 11 2.54 1 mass mass density vol t area mass g t x cm density area g in cm x cm in - = = = = =       ( 29 ( 29 3 2 24.3 14 3 16 2 148.3 / Mg NO x x g mol = + + =
Background image of page 1

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

View Full DocumentRight Arrow Icon
Chem 125 Exam #1 Fall 2010 Ellis 2 5 23 23 23 2 5 2 5 2 5 2 14.0 5 16.0 108.0 / 10.0 1 5 6.02 10 2.78 10 = 3 10 O atoms 1 108 1 MM N O x x g mol gN O mol N O mol O x atoms x x x x x g mol N O mol = + = = 4 17 6 4 4 4 23 4 4 12.0 4 1.0 16.0 / 1.25 10 1 16.0 3.32 10 6.02 10 MM CH x g mol x molecules CH mol CH gCH x x x g x molecules CH mol CH - = + = = 6. If the following equation were balanced using the smallest possible integral coefficients, what would be the coefficient for oxygen? CH
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.

Page1 / 7

2010F_chem_125_exam_1--44gt60xx3aNswers-e-e-ee-e-e - Chem...

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