Semester I Review ANSWERS

Semester I Review How many sig-figs are found in each number? 0.345 3 0.345 3 3005 4 300 1 3.002 4 0.00023 2

Semester I Review Round each number to three sig-figs. 45678 45700 45678 45700 0.002894 0.00289 23.76 23.8 100.5 100. 56.799 56.8

Semester I Review Which of the following is a mixture. Pure water compound Clean air homogenous mixture Iron (II) oxide compound Salt water homogenous mixture Carbon dioxide compound

Semester I Review Which of the following is a chemical change. Cutting paper physical Boiling water physical Rusting iron chemical Burning gasoline chemical

Complete the table using the given numbers Symbol Mass # Atomic # Protons Neutrons Electrons X - _25__ 25 10 15 Y - 35 35 14 21 Z - _56__ 56 31

Semester I Review Calculate the average atomic mass given the following data: element Y has three isotopes 35.0% = 23.5 amu, 55.0% = 25.0 amu and 10.0% = 26.0 amu. (35x23.5) + (55x25.0) + (10x26.0) = 24.6 100

Semester I Review 25.0 grams of a given metal displaces 44.2 mL of water; what is the density of the metal? 25.0g/44.2mL = 0.566g/mL

Semester I Review What did each scientist contribute to the development of the modern atom. Dalton = proof of the atom Thomson = cathode rays are electrons Rutherford = dense positive nucleus, electrons outside nucleus, atom mostly empty space Milliken = mass to charge ratio of the electron

Determine if the data below is accurate, precise, both, or neither Trial # Measurement True Value = 34.50 1 34.56 Accurate and precise 2 34.45 3 34.78 Calculate the percent error using the average of the measurements. (34.60 – 34.50) x100 = 0.2899% 34.50

Semester I Review The splitting of a nucleus is known as ___fission _____. The combining of two small nuclei to form a larger one is known as ____Fusion______. Give the formula of an alpha particle and beta particle.

Semester I Review Decay of polonium-218 by alpha () emission.  + Decay of carbon – 14 by beta emission  + Decay of Thorium - 232 by an electron capture + 

Semester I Review The half-life of phosphorous-30 is 2.5 min. If you start with 55 g of phosphorus-30, how many grams would remain after 27.5 min? Mfinal = (55g)(.5)11 = 0.027g

Semester I Review Calculate the specific heat of an unknown metal, given that 25.0g of the metal lost 3570 J of energy during a temperature change from 100.0oC to 25.0oC c = 3570J / (25.0g)x(75.0oC) c = 1.90 J/goC

Semester I Review Identify each of the letters on the graph and explain what is occurring. C = solid warming/cooling D = Phase change solid to liquid or vice versa E = liquid warming/cooling F = phase change liquid to gas or vice versa G = gas warming/cooling C D E F G

Semester I Review Label the solid, liquid, and gas regions on the graph. Label the triple point and critical point At 600oC and 90 atm, what phase is yummygum in? liquid Label the solid, liquid, and gas regions on the graph. Label the triple point and critical point At 600oC and 90 atm, what phase is yummygum in? Critical point liquid solid Triple point gas

Semester I Review Give the formula for the following compounds 1) iron (II) arsenide Fe3As2 2) lead (II) sulfate PbSO4 3) lead (IV) hydroxide Pb(OH)4 4) copper (II) acetate Cu(C2H3O2)2 5) beryllium chloride BeCl2 6) ammonium chromate (NH4)2CrO4 7) silver oxide Ag2O 8) potassium sulfide K2S

Semester I Review Give the name of the following compounds 1) NaBr Sodium Bromide 2) Sc(OH)3 Scandium (III) Hydroxide 3) V2(SO4)3 Vanadium (III) Sulfate 4) NH4F Ammonium Fluoride 5) CaCO3 Calcium Carbonate 6) NiPO4 Nickel (III) Phosphate 7) Li2SO3 Lithium Sulfite 8) Zn3P2 Zinc Phosphide 9) Sr(C2H3O2)2 Strontium Acetate 10) Cu2O Copper (I) Oxide

Semester I Review Name the compounds H2SO3 Sulfurous Acid H2S Hydrosulfuric acid H3PO4 Phosphoric acid HCN Hydrocyanic acid H3P Hydrophosphoric acid HBr Hydrobromic acid HClO Hypochlorous acid

Semester I Review Give the formula for the following compounds hydrofluoric acid HF hydroselenic acid H2Se carbonic acid H2CO3 nitrous acid HNO2 sulfuric acid H2SO4 hydrobromic acid HBr Chlorous acid HClO2

Semester I Review Antimony tribromide SbBr3 Silicon difluoride SiF2 Tetracarbon octahydride C4H8 Dinitrogen monoxide N2O Pentaphosphorous decoxide P5O10 Sulfur hexachloride SF6

Semester I Review P2O5 Diphosphorous pentoxide SO2 Sulfur dioxide NO2 Nitrogen dioxide AsCl3 Arsenic trichloride P4H8 Tetraphosphorous octahydride

Semester I Review Balance and classify the reactions _2_ C8H18 + _25_ O2  _16_ CO2 + _18_ H2O ____ FeCl3 + _3__ NaOH  ____ Fe(OH)3 + _3__NaCl _4__ P + __5_O2  _2__P2O5 _2__ Na + _2__ H2O  __2_ NaOH + ____H2 _2__ Ag2O  _4__ Ag + ____O2 ____ S8 + _12_ O2  _8__ SO3