E-mail: [email protected] 650 5152 Web-page: www.qmk-com-level.jimdo.com 982 345 541 ADMISIÓN UNI 2013 -2 QMK COM LEVEL CHEMISTRY COURSE – UNI 2013 -2 NATIONAL UNIVERSITY OF ENGINEERING – UNI Lima - Perú 01. Give the chemical names of each of the following familiar compounds. Find the molecular compound. A) Table salt B) Baking soda C) Lime D) Milk of magnesia E) Methane 02. There are two different isotopes of bromine atoms. Under normal condition, elemental bromine consist of Br 2 molecules and the mass of the Br 2 molecule is the sum of the two atoms in the molecule. The mass spectrum of Br 2 consist of three peaks. Mass (amu) Relative Size 157,836 0,2569 159,834 0,4999 161,832 0,2431 Determine the average atomic mass of a bromine atom A) 79,918 B) 79,917 C) 80,916 D) 79,889 E) 79,998 03. Calculate the percentage of nitrogen, by mass, in calcium nitrate also called Norwegian saltpeter. Average atomic mass (amu): Ca = 40, N = 14, O = 16 A) 17,1 % B) 13,71 C) 32,52 D) 16,28 E) 13,17 04. Without using calculator, arrange the following samples in order of increasing numbers of carbon atoms: I. 12 g of 12 C. II. 1 mol C 2 H 2 . III. 9x10 23 molecules of CO 2 . Consider: Avogadro´s Number = 6x10 23 A) I < II < III B) I < III < II C) II < I < III D) II < III < I E) III < I < II 05. How many oxygen atoms are in 159 g of sodium carbonate? Consider: Avogadro´s Number = 6x10 23 Average atomic mass (amu): Na = 23, C = 12, O = 16 A) 1,8x10 24 B) 1,8x10 23 C) 2,7x10 24 D) 2,7x10 23 E) 3,0x10 24 Follow us: QMK COM LEVEL Follow us: Química Preuniversitaria Follow us: @qmkcomlevel

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E-mail: [email protected] � 650 5152

Web-page: www.qmk-com-level.jimdo.com � 982 345 541

ADMISIÓN UNI 2013 -2 QMK COM LEVEL

CHEMISTRY COURSE – UNI 2013 -2

NATIONAL UNIVERSITY OF

ENGINEERING – UNI

Lima - Perú

01. Give the chemical names of each of the following familiar compounds. Find the molecular compound. A) Table salt B) Baking soda C) Lime D) Milk of magnesia E) Methane

02. There are two different isotopes of

bromine atoms. Under normal condition, elemental bromine consist of Br2 molecules and the mass of the Br2 molecule is the sum of the two atoms in the molecule. The mass spectrum of Br2 consist of three peaks.

Mass (amu) Relative Size 157,836 0,2569 159,834 0,4999 161,832 0,2431

Determine the average atomic mass of a bromine atom A) 79,918 B) 79,917 C) 80,916 D) 79,889 E) 79,998

03. Calculate the percentage of nitrogen, by mass, in calcium nitrate also called Norwegian saltpeter. Average atomic mass (amu): Ca = 40, N = 14, O = 16 A) 17,1 % B) 13,71 C) 32,52 D) 16,28 E) 13,17

04. Without using calculator, arrange the following samples in order of increasing numbers of carbon atoms: I. 12 g of 12C. II. 1 mol C2H2. III. 9x1023 molecules of CO2.

Consider: Avogadro´s Number = 6x1023

A) I < II < III B) I < III < II C) II < I < III D) II < III < I E) III < I < II

05. How many oxygen atoms are in 159 g of sodium carbonate? Consider: Avogadro´s Number = 6x1023 Average atomic mass (amu): Na = 23, C = 12, O = 16 A) 1,8x1024 B) 1,8x1023

C) 2,7x1024

D) 2,7x1023 E) 3,0x1024

Preuniversitaria