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FINAL EXAM. REVIEW SLIDES. Atomic Theory. 1) What is the charge, positive or negative, of the nucleus of every atom? The nucleus is positive since the protons are +1 and the neutrons have a charge of 0. 2) Why is an atom electrically neutral ?
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FINAL EXAM REVIEW SLIDES
Atomic Theory 1) What is the charge, positive or negative, of the nucleus of every atom? The nucleus is positive since the protons are +1 and the neutrons have a charge of 0. 2) Why is an atom electrically neutral? There is the same number of protons (+1) and electrons (-1) so their charges cancel out to equal zero. 3) Distinguish between protons, electrons, and neutrons in terms of their relative masses and charges. It may be helpful to construct a table. Protons = mass of 1 amu, charge +1 Neutrons = mass of 1 amu, charge 0 Electrons = mass of 0, charge -1
Atomic Theory Continued Complete the following table.
Atomic Theory Continued 5) Complete the following table:
Atomic Theory Continued 6)What is an isotope? How do isotopes of an atom differ? Isotopes are atoms of the same element with different numbers of neutrons. 7) What is the difference between the mass number and the atomic mass of an atom? Mass number is the number of protons and neutrons of an individual atom. The atomic mass of an element (on the periodic table) is the average mass of all of the isotopes of each element.
Atoms and Electrons Write the long electron configurations for the following: 1) nitrogen____1s22s22p3_______________ 2) nickel ______1s22s22p63s23p64s23d8______________________ 3) calcium _____1s22s22p63s23p64s2_____________________ 4) phosphorus___1s22s22p63s23p3_________________________ 5) copper ______1s22s22p63s23p64s23d9_________________
Ionization EnergyFor each of the following pairs, circle the element that has the larger ionization energy. Use the periodic table to assist you.
Types of Reactions Put numbers in the blanks to balance the following equations. Learn to recognize the distinguishing features of each reaction type. SYNTHESIS _4_P + _5_O2→ ___P4O10 _4_Na + ___O2 → _2_Na2O
Types of Reactions Cont’d DECOMPOSITION: _2_HgO → _2_Hg + ___O2 ___CaCO3 → ___CaO + ___CO2 already balanced
Types of Reactions Cont’d SINGLE REPLACEMENT ___MgCl2 + _2_K → _2_KCl + ___Mg ___Fe + ___CuSO4 → ___Cu + ___FeSO4 already balanced
Types of Reactions Cont’d DOUBLE REPLACEMENT ___K2SO4 + ___BaCl2 → ___BaSO4 + _2_KCl _2_AgF + ___Ca(NO3)2 → _2_AgNO3+ ___CaF2
Types of Reactions Cont’d COMBUSTION: __C3H8+ _5_O2→ __3_CO2+ _4_H2O ___C4H12+ _8_O2→ _4_CO2+ _6_H2O
The Mole Find the Molar Mass of each compound. a. Li2S = (6.941 x 2) + 32.065 = 45.947 b. FeCl3= 55.845 + (35.453 x 3) = 162.204 c. Ca(OH)2 = 40.078 + (15.994 x 2) + (1.008 x 2)= 74.082
The Mole Continued Convert moles to particles. Show all work. a. 45.6 moles of CH4 45.6 x 6.02 x 1023 = 2.75 x 1025 • 1.03 moles of NH3 1.03 x 6.02x 1023 =6.2 x 1023
The Mole Continued Convert particles to moles. Show all work. a. 7.83 × 1024 molecules Ethanol 7.83 x24 ÷ 6.02 x 1023 = 13.01 moles • 5.02 × 1026 Au atoms 5.02 x 1026 ÷ 6.02 x 1023 = 833.9
The Mole Continued Convert grams of a sample into moles. Show all work. • 56 grams of CO2 56 ÷ 44.0098 = 1.273 moles b. 1060 g C6H6 1060 ÷ 78.114 = 82800.84
The Mole Continued Convert moles of a sample into grams. Show all work. a. 45 moles of CaCl2 45 x 110.984 = 4994.28 b. 760 moles of N2O5 760 x 108.0104 = 82087 g
Stoichiometry Calculate the mass of sulfur needed to react with 40.0 g of copper. _16__Cu + ___S8 → _8__Cu2S 40 .0 g 10.0 g ÷ molar mass of Cu x molar mass of S8 (63.546) (256.52) 0.629X 1 0.039 16 x molar ratio
Stoichiometry Continued Calculate the mass of silver formed by heating 10.0 g of silver oxide. ___Ag2O → ___Ag + ___O2