Question

NA = 6.022×1023 Ek = 1 2 mv2 T(F°) = T(C°) × 9 5 + 32 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

1) Combustion analysis of an unknown compound containing only carbon and hydrogen produced 17.02 g of CO 2 and 8.721 g of H2O. What is the empirical formula of the compound? A) C2H5 B) CH2 C) CH D) C3H8 1)

2) How many moles of CuO can be produced from 1.80 mol of Cu2O in the following reaction? 2 Cu2O(s) +O 2(g) →4 CuO(s) A) 0.900 mol B) 1.80 mol C) 7.20 mol D) 3.60 mol 2)

3) The diameter of the nucleus of an atom is approximately 1 × 10 -13 cm. If 1 nm is equal to 10 Ångstroms, what is the diameter of the nucleus in Ångstroms? A) 1 × 10 -5 Å B) 1 × 10 -23 Å C) 1 × 10 -7 Å D) 1 × 10 -8 Å 3)

4) Which element has the chemical symbol, Au? A) lead B) antimony C) americium D) gold 4)

5) Which statement about elemental analysis by combustion is not correct? A) Oxygen is determined from the amount of H2O formed. B) Hydrogen is determined from the amount of H2O formed. C) Only carbon and hydrogen can be determined directly from CO2 and H2O. D) Carbon is determined from the amount of CO 2 formed. 5)

6) Which one of the following contains 38.7% carbon by mass? A) CH3NH2 B) CO2 C) CH4 D) C2H2 6)

7) What is the stoichiometric coefficient for water when the following equation is balanced using the lowest whole-number coefficients? ________ C3H8O(l) + ________ O2(g) → ________ CO2(g) + ________ H2O(l) A) 8 B) 6 C) 3 D) 7

8) Which are isotopes? An atom that has an atomic number of 12 and a mass number of 26 is an isotope of an atom that has A) an atomic number of 13 and a mass number of 26. B) 12 protons and 14 neutrons. C) 12 neutrons and 14 protons. D) an atomic number of 12 and a mass number of 24

Answer 1