1) What is the coefficient for O2 when the equation for the combustion of C5H12 to CO2 and H2O is balanced? A) 6 B) 7 C) 8 D) 9 2) What is the coefficient for O2 when this equation is balanced with the lowest whole number coefficients? C3H7OH+O2CO2+H2O A) 4 B) 10 C) 9 D) 5 3) In what type of reaction are there more reactant substances than product substances? A) Combination B) Decomposition C) Single displacement D) Double displacement 4) What is the percent by mass of salt in a mixture that contains 150g of salt, 1.2kg of flour and 650g of sugar? A) 8.1% B) 19% C) 7.5% D) 0.075% 5) An atom of chlorine has how many valence electrons? A) 4 B) 6 C) 7 D) 2 6) Which of the following represents a pair of isotopes? A) 614C,714N B) 11H1212H C) O2,O3 D) 1632S1632s2 7) Which of the following is a pure substance? A) Sugar B) Sand C) Maple syrup D) Goid 8) When a substance is oxidized it is called a(n): A) reducing agent B) oxidizing agent C) both D) neither 9) What is the mass of 3.61 moles of Ca ? A) 40.0g B) 0.090g C) 145g D) 150g 10) What is the name and symbol of an ion that has 26 protons and 23 electrons? A) Mn+2 B) Fe+3 C) Fe+2 D) Mn+3 11) How long is 1cm ? A) 1mm B) 10mm C) 100mm D) 0.01mm 12) Which one of the following carries no electrical charge? A) An electron B) A cation C) A neutron D) A proton 13) Which of the following elements has a filled valence shell? A) P B) Se C) Ne D) 0 14) Express the number 109,000 using scientific notation. A) 1.09106 B) 1.09105 C) 1.09107 D) 1.09104