Transcript ANS
Chemistry I H Final Exam Review Questions What prefix means 1000 ANS: kilo What prefix should have 1000 written in front of it in a factor label step? ANS: milli What has been measured if a quantity has a cubic length (like cm3) as its units? ANS: volume 500. mm = ____ km ANS: 0.000500 km 14 L = _____ mL ANS: 14,000 If the true value is 5.0 and the observed value is 3.0, what is the percent error? ANS: 40% What is 452 in scientific notation? ANS: 4.52 x 102 How many significant digits are in 0.00670 ANS: 3 Is a chocolate chip cookie heterogeneous or homogeneous? ANS: heterogeneous Is dissolving a physical or chemical change? ANS: physical What changes form new substances? ANS: chemical What kind of change occurs when a compound is broken into elements? ANS: chemical What two subatomic particles have the largest mass ANS: protons and neutrons What parts of an atom did Dalton know about? ANS: None. He thought an atom was indivisible What are atoms of an element with different numbers of neutrons called? ANS: isotopes What standard isotope was assigned a whole-number mass? ANS: carbon-12 How many neutrons are in polonium-210? ANS: 126 Who discovered the charge to mass ratio of electrons? ANS: J.J. Thomson What color of light has the least energetic photons? ANS: red Who first used energy levels to describe electrons? ANS: Bohr Did Bohr consider the electron to be a particle or a wave? ANS: particle What does the principal quantum number describe about an electron? ANS: the energy of the electron What shape are orbitals of “s” sublevels? ANS: spherical How many electrons can be in the 4th energy level? ANS: 32 What is the electron configuration for carbon? ANS: 1s22s22p2 What does it mean to say an electron exhibits wave-particle duality? ANS: It behaves like waves and particles. What elements are poor conductors of electricity? ANS: nonmetals Today the periodic table is arranged by atomic number. Mendeleev arranged his table by ANS: atomic mass What sublevel ending do transition metals have? ANS: d Why does atomic size decrease from left to right across a period? ANS: Because of an increasing nuclear charge. Which requires less energy, removing the first electron from an atom or removing a second one? ANS: Removing the first. With what noble gas do Ca2+ and Cl1- have the same electron configuration? ANS: argon How many sulfur atoms are in the formula for aluminum sulfate? ANS: 3 What is the correct formula for calcium nitride? ANS: Ca3N2 What is the correct name for BaF2? ANS: barium fluoride What is the formula for sulfur dioxide? ANS: SO2 What is the formula for iron(II) iodide? ANS: FeI2 What is the formula for sodium carbonate? ANS: Na2CO3 In the reaction Br2 + 2 NaI 2 NaBr + I2 which element is more active Br or I? ANS: Br What type of reaction has no + on the left of the yield sign? ANS: decomposition What type of reaction has no + on the right of the yield sign? ANS: synthesis What is a solid that results from aqueous solutions called? ANS: precipitate How many atoms are in 1 mole of silver? ANS: 6.02 x 1023 What is the mass of 1 mole of silver? ANS: 107.9 g What is the mass of 1 mole of carbon dioxide? ANS: 44.0 g How many moles of oxygen are in 1 mole of H2SO4 ANS: four What is the molarity of a solution if 20.0 g of sodium hydroxide is dissolved in 150 mL of solution? ANS: 3.3M What is the molarity of Li+ in 2.0 M Li3N? ANS: 6.0M Li+ How many molecules are in 88 g of carbon dioxide? ANS: 1.2 x 1024 molecules