General Chemistry 1311

The value of (triangle) E for a system that performs 111 kJ of work and it's surroundings and gains 89 kJ of heat is?

-22

Calculate (triangle)H° for the following reaction: Enthalpy of formation (H°f) Fe2O3 + 3CO = Fe + 3CO2 Fe2O3: -824.2 kJ/mol reactant CO: -110.5 kJ/mol reactant CO2: -393.5 kJ/mol product Use: Enthalpy change = €[H°f(product)] - €[H°f(reactant)] A. 541.2 kJ B. 320.02 kJ C. -24.8 kJ D. 24.8 kJ E. -541.2 kJ

-24.8 kJ

Calculate the (triangle)H+ run for this reaction using bond energies: CH4(g) + 2O(g) = CO2(g) + 2H2O(g) (Hint: (triangle)H+ € (bond energies of reactants) -€ (Bond energies of products) Bond: C-H, C-O, O-O,O-H Bond energy: 413 kJ/mole, 799 kJ/mole, 495 kilojoules/mole, 463 kJ/mole A) -9808 kJ/ mol B) 9808 kJ/ mol C) -354 kJ/ mol D) 354 kJ/ mol E) -165 kJ/ mol

-9808 kJ/ mol

Calculate the number of moles of BaCl2 in a 4.5g sample of BaCl2. (Use: moles=g/mw) •56 Ba 137 • 56 Ba 137 •17 Cl 35.5

0.0216 moles

How many moles of gases are there in a 45.00 L container at 25°C and 500 mm Hg? (Hint: the universal gas constant: R=0.0821 (L atm)/(mol K): •PV = nRT •1atm = 760 mm Hg •Kelvin = Celsius+ 273 A) 1.21 mol B) 6.11 mol C) 2.07 mol D) 0.630 mol E) 18.4 mol V=45.0 L, T=25+273=298°K P=500mmHg x 1.0 atm/760mmHg = 0.658 atm 0.658a x 45.0L = n x0.0821L.atm/(mol.K)x 298.0°K=

1.21 mol

In a butane lighter, 9.7 g of butane (C4H2O) burns with 14.7 g of O2 to form 29.3 g of CO2 and how many grams of water? C4H1O + O2 = 4CO2 + 5H2O (Hint: moles=g/mw Use: 6C12, 1H1, 8O16) A) 54.3g B) 14.98g C) 55g D) 67g E) 42.3g

14.98g

The number of neutrons in a uranium 92. 238 atom is: (hint: subtract atomic number and mass number) A) 92 B) 238 C) 146 D) 330 E) none of the above 238-92=

146

The temperature of a 12.58 g sample of calcium carbonate [CaCO3 (S)] increases from 23.6 Celsius to 38.3 Celsius. If the specific heat of CaCO3 is 0.82, how many levels of heat are absorbed during this process?

151.63 J

When heat is added to 50.6 g of liquid, the liquid temperature rises by 1.50 Celsius. The liquid specific heat capacity is 242 J/gC. How much of heat was added to the liquid? (Use: he equals Mass x specific heat x change in temp) A) 124.39 J B) 165.28 J C) 180.45 J D) 183.67 J E) 194.50 J 50.6g= water, 1.50°C = change in temperature, 242 J/gC = specific heat 50.6g x 1.50°C x 242 J/gC=

183.67 J

Determine the answer for the equation below with correct numbers of sig figs? 3.15 x 13.2 / 0.218

189

The electron configuration of Li+ is:

1s2 2s1

The electronic configuration for element No is?

1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d8

When the following equation is balanced, final all coefficients (W, X, Y, and Z) for the following: W. CaCl2(s)+ X. O2(g) = Y. CaO(s) + Z. Cl2(g)

2 1 2 2

Convert 0.0254 kg to grams

2.54 g

Calculate the melody of a solution that contains 70.00 g of H2SO4 and 208.00 mL of a solution? Use: 1H1, 16S 3, 8O 16 A) 5.25 M B) 2.55 M C) 6.68 M D) 8.64 M E) 8.78 M

2.55 M

Determine the formula weight of MgS04 7H2O (12Mg 24.3050, 16S 32.066, 8O 15.994, 1H 1.00794)

246.41 amu

Convert 25 Celsius to Kelvin (Hint: 0°C + 273.15 = 273.15°K) 25°C + 273.15 =

298

Calculate the bond order of N2 molecule

3

The correct number of significant figures in 0.0351 is?

3

How many sigma bonds and how many pi bonds does acetylene (C2H2) molecules contain? A) 5 sigma and 1 pi B) 2 sigma and 3 pi C) 3 sigma and 1 pi D) 2 sigma and 2 pi E) 3 sigma and 2 pi

3 sigma and 2 pi

Which set of three quantum numbers (n,l,ml) corresponds to a 3p orbital? A) 3,1,0 B) 3,0,1 C) 3,3,1 D) 3,0,0 E) 3,2,0

3, 1, 0

Calculate the kinetic energy in joules of an 80.0 g bullet traveling at 300 m/s (Hint: kinetic energy = (1/2) x m x V2) A) 1.20 x 104 J B) 3.60 x 103 J C) 12.0 J D) 80.0 J E) 3,60 x 106 J

3.60 x 103 J

If an airplane speed is 750 m/hr, what is its speed in m/s? (hint 1 mile = 1.609 km)

335.2 m/s (750 mi/ 1 hr x 1.609/ 1 mi x 1000 m/ 1 km x 1 hr/ 3600 sec)

Choose the correct number of protons, electrons, and neutrons in Br- (Bromide) ion 35 Br 80

35, 36, 45 (36 because it loses an e- [Br-])

Choose which balanced molecular equation for the following word-equation is correct Zinc phosphoric acid = Zinc phosphate + hydrogen gas (Hint: phosphoric acid= H3PO4) A) 3Zn + 2H3PO4 = Zn3(PO4)2 + 3H2 B) 3Zn + H3PO4 = Zn3(PO4)2 + 3H2 C) 3Zn + 2H3PO4 = Zn3(PO4)2 + 6H2 D) 6Zn + 2H3PO4 = Zn3(PO4)2 + 3H2 E) none of the above

3Zn + 2H3PO4 = Zn3(PO4)2 + 3H2

Which of the following elements has the largest atomic radius? A) 9F B) 16S C) 11Na D) 28Ni E) 55Cs

55Cs

Calculate the average atomic mass from the percent natural abundance and isotopic mass for gallium that has two natural isotopes (Ga- 69, 68.9257 amu abundance 60.00%) (Ga- 71, 70.9247 amu abundance 40.00%)

60.725 amu

A sample of H2 gas weighing 9.49 g occupies ______ L at 353°K and 2.00 atm R= 0.0821L atm/mol K: (Use 1H 1/ Pv = net and moles = g/mw A. 109.2L B. 68.7L C. 147.3L D. 77.3L E. 54.7L

68.7 L

The number of metalloids in the periodic table is

7

What is the automatic number of Ta?

73

What formula is most likely when aluminum and oxygen are together?

Al2O3

Of the species below, only __________ is not an electrolyte a) HCl b) Rb2SO4 c) Ar d) KOH e) NaCl

Ar

The element that ends with 2S2 electron configuration is: A. Li 3 B. He 2 C. Be 4 D. B 5 E. C 6

Be

If a compound has a melting point of 22°C, which of the following statement is true? A. Above 22°C and the compound is a solid B. Above 22°C and the compound is a gas C. Below 22°C and the compound is a solid D. Below 22°C and the compound is a gas E. n o a

Below 22°C and the compound is a solid

What is the electron a geometry for an H2O molecule?

Bent (V-shape) electronic

Which of the following elements is a non-metal? A. He B. Be C. Cl D. Both A and B E. Both A and C

Both A and C

Which of the following elements has six valence electrons? A. 20 Ca B. 13 Al C. 8 O D. 16 S E. Both C and D

Both C and D

Of the reactions below, which one is a combustion reaction? A) NH4Cl = NH4+ + Cl- B) NH4Cl = NH3 + HCl C) CH4 + 2O2 = CO D) Mg + Cl2 = MgCl2 E) Fe2O3 + 3CO = Fe + 3CO2

CH4 + 2O2 = CO

Which of the following element is an alkali earth metal? A. Sodium grp1 B. Calcium grp4 C. Aluminum grp3 D. Potassium grp1 E. Lithium grp1

Calcium group 4

Ever reaction of 27.5 g of Fe with 63.1 g of Cl2 produced 60.4 g of FeCl3, what is the limiting reagent? (26 Fe 55.84, 17 Cl 35.5)

Cl2

A chemical bond formed by two atoms sharing one or more pairs of electrons is called a(n) _______ bond.

Covalent

What is the Net ionic equation for the following formula unit equation? Cu(NO3)2(aq) + H2S(aq) = CuS(s) + 2HNO3(aq)

Cu2(aq) + S2(aq) = CuS(s)

Which is correct molecular formula for copper (II) sulfate? A) Cu2SO4 B) CuSO4 C) Cu(SO4)3 D) CuSO3 E) n o a

CuSO4

Which Lewis structure is not correct?

D.

When C=C is converted into a C-C, The bond strength will (P)______ and the bond length (Q)______ A) + - B) + + C) - - D) - + E) stay the same

Decrease and increase

What is the correct name of N2O5?

Dinitrogen pentoxide

Which of the following properties is based on the attraction of an atom for electrons in a chemical bond? A) binding energy B) mass defect C) electron affinity D) ionization energy E) electronegativity

Electronegativity

Which element has the highest number of valence electrons? A. 11 Na B. 12 Mg C. 7 N D. 8 O E. 9 F

F

Which of the following is soluble in water at 25°C (hint: consult the following table) A) Fe3 (PO4)2 (S) B) FeS (s) C) FeS (NO3)2 (aq) D) FeCO3 (s) E) Fe(OH)2 (s)

FeS (NO3)2

Which of the following has the highest metallic character? A) Mg12 (metal) B) N7 (nm) C) O8 (nm) D) Fr87 (m) E) Br35 (nm)

Fr

The net ionic equation for the following reaction is? HCl + NaOH + H2O HCl(g) + NaOH(s) = NaCl(s) + H2O(l)

H+ + OH- = H2O

What is the formula for sulfuric acid

H2SO4

Which of the following is the strongest acid?

HI

Which one of the following is not an intensive property?

Mass

Which of the following formula is incorrect?

Mg2O (Mg has +2 charge and O has a -2 charge, it would be MgO)

Manganese has the oxidation number of +7 in? A) (MnF6)3 B) Mn2O7 C) MnO42 D) [Mn(Cn)6]1 E) none of the above

Mn2O7

Which molecule is polar? A) BF3 B) CCl4 C) CO2 D) SO2 E) N2 (SO2=(2.5-3.5)=1 : difference up to 1.9 polar)

N2

Calculate the empirical formula when a sample contains 1.2 g of nitrogen, and 1.5 g of oxygen. A) NO4 B) NO2 C) N3O2 D) NO E) NO2 1.2g N 14.0 amu, 15g O 16.0 amu 1.2g N x 1 mol N/ 14.0g N = .086/.086=1 1.5g O x 1 mol O/ 16.0 O = .094/ .086= 1.0 Empirical formula is

NO

Which pair of elements would exhibit the greatest similarity in their physical and chemical properties?

Na and Cs

Which particle of the atom has a neutral charge?

Neutron

Which I am below is isoelectronic with neon (Ne) A. Li+ B. C2+ C. O- D. O2- E. N2-

O2-

The subatomic particles that have similar masses are?

Protons and neutrons

The silicone atom in a SiH4 molecule is _______ hybridized in the H-Si-H bond angles are ______ A. SP2 120 B. SP2 109.5 C. SP3 120 D. SP3 109.5 E. n o a

SP3 109.5°

For students A-D determine the molarity of an NaOH solution experimentally and got the following results, the correct Millatti for NaOH solution is 0.1092 M. which The students data has good precision relatively poor accuracy? A) student A. 0.1091 M. 0.1092 M. 0.1093 M. B) student B. 0.1098 M. 0.1099 M. 0.1098 M. C) student C. 0.1082 M. 0.1096 M. 0.1100 M. D) student D. 0.1078 M. 0.1088 M. 0.1082 M. E) None of the above

Student B. 0.198 M. 0.1099 M. 0.1098 M.

Which of the following is not a diatomic species in molecular state?

Sulfur

What is the condensed electron configuration of bromine: 35 Br 79.9? A) [Ar] 4s2 3d10 4p5 B) [Ar] 4s4 3d5 4p10 C) [Ar] 4s2 3d10 4p6 D) [Kr] 4s2 3d7 E) [Kr] 4s2 4p5

[Ar] 4s2 3d10 4p5

A combination of sand salt and water is an example of?

heterogenous mixture

The initial or tentative explanation of an observation is called a(n)?

hypothesis