Chem: Mole Chapter Test – Flashcards
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which of the following is not an empirical formula?
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C2N2H8
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how many atoms are in 3.5 moles of arsenic atoms
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2.1 x 10^24 atoms
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what is the empirical formula of a compound that is 40% sulfur and 60% oxygen by weight
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SO3
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how many moles of tungsten atoms are in 4.8 x 10^25 atoms of tungsten
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8.0 x 10^1 moles
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which combination of temperature and pressure correctly describes standard temperature and pressure, STP
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0 degrees C and 101 kPa
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how many molecules are in 2.10 mol CO2
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1.26 x 10^24 molecules
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which of the following compounds has the lowest percent gold content by weight
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AuI3
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which of the following compounds has the highest oxygen content by weight
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H2O
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what is the percent by mass of carbon in acetone, C3H6O
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62.1%
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butanol is composed of carbon, hydrogen, and oxygen. if 1.0 mol of butanol contains 6.0 x 10^24 atoms of hydrogen, what is the subscript for the hydrogen atom in C4H2O
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10
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what is the molar mass of (NH4)2CO3
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96 g
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representative particle
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an atom, an ion, or a molecule, depending upon the way a substance commonly exists
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mole
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the SI unit used to measure amount of substance
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Avogadro's number
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the number of representative particles of a substance present in 1 mole of that substance
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percent composition
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the percent by mass of each element in a compound
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standard temperature and pressure (STP)
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0 degrees and 1 atm
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empirical formula
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the smallest whole number ratio of the atoms in a compound
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molar volume
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the volume occupied by a mole of any gas at STP
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molar mass
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the mass of a mole of any element or compound
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atomic mass
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the number of grams of an element that is numerically equal to the atomic mass of the element in amu
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given 1.00 mole of each of the following gases at STP, which gas would have the greatest volume
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all would have the same volume
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what is the number of moles in 9.63 L of H2S gas at STP
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.430 mole
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how many moles of CaBr2 are in 5.0 grams of CaBr2
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2.5 x 10^-2 mol
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what is true about the molar mass of nitrogen gas
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the molar mass is 28.0 g
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what is the mass of oxygen in 250 g of sulfuric acid, H2SO4
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160 g
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which of the following elements exists as a diatomic molecule
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neon
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the ratio of carbon atoms to hydrogen atoms to oxygen atoms in a molecule of dicyclohexyl maleate is 4 to 6 to 1. what is its molecular formula id its molar mass is 280 g
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C16H24O4
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which expression represents the percent by mass of nitrogen in NH4NO3
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28 g N/80 g NH4NO3 x 100%
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what is the mass in grams of 5.90 mol C8H18
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673 g
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for which of the following conversions does the value of the conversion factor depend upon the formula of the substance
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mass of any substance to moles
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which of the following is not true about atomic mass
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the atomic mass is 12 g for magnesium
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what is the percent composition of carbon, in heptane, C7H16
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84%
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a 22.4 L sample of which of the following substances, at STP, would contain 6.02 x 10^23 representative particles
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oxygen
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if the density of a noble gas is .902 g/L, at STP, that gas is
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Ar
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which of the following sets of empirical formula, molar mass, and molecular formula is correct
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CH4N, 90 g, C3H12N3
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what is the number of moles in 500 L of He gas at STP
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22 mol
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if the density of an unknown gas Z is 4.50 g/L, at STP, what is the molar mass of Z
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101 g/mol
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what information is needed to calculate the percent composition of a compound
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the formula of the compound and the atomic mass of its elements
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how many hydrogen atoms are in 5 molecules of isopropyl alcohol, C3H7O
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35
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what is the empirical formula of a substance that is 53.5% C, 15.5% H, and 31.1% N by weight
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C2H8N
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the mass of a mole of NaCl is the
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molar mass
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what SI unit is used to measure the number of representative particles in a substance
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mole
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the volume of one mole of a substance is 22.4 L at STP for all
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gases
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what is the density at STP of the gas sulfur hexafluoride, SF6
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`6.52 g/L
