Semester I Review

ANSWERS

Semester I Review

How many sig-figs are found in each number?0.345 33005 4300 13.002 40.00023 2

Semester I Review

Round each number to three sig-figs.45678 457000.002894 0.0028923.76 23.8100.5 100.56.799 56.8

Semester I Review

Which of the following is a mixture.Pure water compoundClean air homogenous mixture Iron (II) oxide compoundSalt water homogenous mixtureCarbon dioxide compound

Semester I Review

Which of the following is a chemical change.Cutting paper physicalBoiling water physicalRusting iron chemicalBurning gasoline chemical

Symbol Mass # Atomic # Protons Neutrons Electrons

X - _25__ 25 10 10 15 10

Y - 35 35 14 14 21 14

Z - _56__ 56 25 25 31 25

Complete the table using the given numbers

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 atomThomson = cathode rays are electronsRutherford = dense positive nucleus,

electrons outside nucleus, atom mostly empty space

Milliken = mass to charge ratio of the electron

Trial # Measurement True Value = 34.50

1 34.56

Accurate and

precise

2 34.45

3 34.78

Determine if the data below is accurate, precise, both, or neither

Calculate the percent error using the average of the measurements. (34.60 – 34.50) x100 = 0.2899%

34.50

Semester I Review

1. The splitting of a nucleus is known as ___fission _____.

2. The combining of two small nuclei to form a larger one is known as ____Fusion______.

3. Give the formula of an alpha particle and beta particle.

He42 0

1

Semester I Review1. Decay of polonium-218 by alpha ()

emission.1. +

2. Decay of carbon – 14 by beta emission

3. +

4. Decay of Thorium - 232 by an electron capture

5. +

Po21884

He42 Pb214

82

C146 0

1 N147

Th23290 0

1 Ac23289

Semester I Review

1. 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?

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

solid

liquid

gas

Triple point

Critical point

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

Semester I Review