Chemical Bonds and Thermochemistry | Baamboozle - Baamboozle

An iron block with a mass of 0.11 kg absorbs 504J of heat energy. What is the temperature rise in K? (C = 0.448 Jg-1K-1)

10.23

1.10

1.02E4

9.78E-2

Which of the following does NOT have an enthalpy of 0 kJ/mol

H2O(l)

I2(s)

S8(s)

Co(s)

What is the electron and moelcular geometry of chlorate ion? Is it polar?

Electron: tetrahedral. Molecular : Trigonal pyramidal. : It is polar because it is both asymmetric and it is an anion. (draw please w lone pair on chlorinei

What is the electron and moelcular geometry of sulfate ion? Is it polar?

It is tetrahedral for both electron and molecular geometry. Since it is an anion it is polar

Why is CHCl3 more polar than CCl4?

CCl4 is symmetric and therefore no net dipole; CHCl3 is asymmetric

What is the electron and molecular geometry for carbon dioxide. From this data, is it polar?

Electron: linear. Molecular: linear. - It is symmetric therefor NOT POLAR

Which molecule is most polar?

CHF 3

CF 4

CCl 4

CClF 3

Which combination describes the sulfate(IV) ion, SO32– (also known as sulfite ion)?

D

C

B

A

The Lewis (electron dot) structure of the ethanedioate ion is shown. Outline why all the C–O bond lengths in the ethanedioate ion are the same length

electrons delocalized «across the O–C–O system» or RESONANCE

Which series shows the correct order of metallic bond strength from strongest to weakest?

Mg > Na > K > Rb

Rb > K > Na > Mg

Mg > Rb > K > Na

Na > K > Rb > Mg

What is the enthalpy change of combustion of urea, (NH2)2CO, in kJ mol−1? 2(NH2)2CO(s) + 3O2(g) → 2CO2(g) + 2N2(g) + 4H2O(l)

1/2 [2 × (−394) + 4 × (−286) −2 × (−333)]

2 × (−394) + 4 × (−286) −2 × (−333)

2 × (−333) −2 × (−394) −4 × (−286)

1/2 [2 × (−333) −2 × (−394) −4 × (−286)]

Consider the following reaction: N2 (g) + 3H2 (g) ⇌ 2NH3 (g) Which calculation gives ΔHΘ, in kJ, for the forward reaction?

y + 3x − 6z

Which combination will give you the enthalpy change for the hydrogenation of ethene to ethane, Δ H3 ?

− Δ H 2 + Δ H 1 − Δ H 4

Which change of state is exothermic?

NH3(g) → NH3(l)

CO2(s) → CO2(g)

H2O(l) → H2O(g)

Fe(s) → Fe(l)

Which statement is correct about the reaction shown? 2SO2(g) + O2(g) → 2SO3(g) ΔH = -196 kJ

98 kJ of energy are released for every mole of SO2(g)

196 kJ of energy are released for every mole of SO2(g)

98 kJ of energy are absorbed for every mole of SO2(g)

196 kJ of energy are absorbed for every mole of SO2(g)

For which of the following is the sign of the enthalpy change different from the other three?

2Cl(g) → Cl2(g)

Na(g) → Na+(g) + e-

CaCO3(s) → CaO(s) + CO2(g)

CO2(s) → CO2(g)

What is the energy change (in kJ) when the temperature of 20 g of water increases by 10C?

(20 x 10 x 4.18)/1000

20 x 10 x 4.18

2 x 283 x 4.18

(20 x 283 x 4.18)/1000

The average bond enthalpies for O-O and O=O are 146 and 496 kJ/mol respectively. What is the enthalpy change, in kJ, for the reaction below? H-O-O-H(g) → H-O-H(g) + ½O=O(g)

-102

What is ΔH for the reaction below in kJ? CS2(g) + 3O2(g) → CO2(g) + 2SO2(g) (ΔHf (kJ/mol): CS2(g) = -110, CO2(g) = -390, SO2(g) = -290)

-860

The temperature of a 2.0 g sample of aluminum increases from 25C to 30C. How many joules of heat energy were added? (Specific heat of aluminum = 0.90 J/gK)

9.0

What energy changes occur when chemical bonds are broken?

Energy is absorbed when they are broken

Energy is released when they are broken

It depends on the type of bond

it depends on the state of matter

Consider the following equation for the combustion of hydrogen: H2(g) + 1/2 O2(g) → H2O(g) + 243 kJ In order to produce 1215 kJ of heat, how many grams of H2 must burn?

10.0 g

12.0 g

0.250 g

8.00 g

A chemical system in which neither energy nor matter can flow into or out of a system is described as

an isolated system

a closed system

an open system

a chemical system

In an exothermic reaction, the temperature of the surroundings increases because the molecules in the surrounding have

a greater kinetic energy

a lower potential energy

a greater potential energy

a lower kinetic energy

The heat released during the combustion of C3H8(g) (propane) to produce CO2(carbon dioxide) gas and water vapour is 2222 kJ/mol of C3H8(g). Which of the following is the correct chemical equation for the reaction?

C3H8(g)+ 5O2(g) → 3CO2(g) + 4H2O (g) + 2222 kJ

C3H8(g) + 5O2(g) + 2222 kJ → 4H2O (g) + 3CO2(g)

C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O (g) ΔH = +2222 kJ

3CO2(g) + 4H2O(g) → 5O2(g) + C3H8(g) ΔH = –2222 kJ

Refers to a chemical reaction or physical change in which heat is absorbed. That is, the system gains heat; q is positive.

endothermic

a property of a substance that is independent of the amount of the substance present.

intensive (e.g. mp, bp, density)

How many resonance structures are there for sulphite ion? How many lone pairs?

1 lone pair and 3 resonance structures.

[HL question] if you are in SL 5 marks automatically. Full marks for answer 1 guess only: Which of the following is a non-spontaneous process?

Graphite turns into diamond

Water freezes below 0°C.

Iron exposed to water and oxygen forms rust

A gas diffuses into a room until it is equally distributed.

What is the molecular geometry of the carbonate ion? What would be the angles?

trigonal planar; 120 degrees

Which of the following is a state function?

temperature

work

force

heat

Best explanation here that graphite is softer than diamond

layers can slide/move

graphite is in a tetrahedral arrangement

every carbon atom has a strong bond to the other

the carbons have 4 bonds

What would be the best use of graphite?

electrode

lubricant because it is soft and slippery with weak forces

used in drill heads

decorative stone for rings

Give at least 2 (two) ways to refer to this adorable looking allotrope of carbon

any 2: Bucky ball OR C-60 OR fullterene OR buckminsterfullerene

How many covalent bonds does graphite have?

3

Why do MOLTEN ionic solids conduct electricity?

When an ionic substance is molten the ionic lattice is broken down allowing the ions to move freely and so conduction occurs.

Why do ionic solids NOT conduct electricity?

This is due to the fact that ions are not free to move in a solid as they are arranged in an ionic lattice.

Which of the following would you expect to have the highest melting point?

magnesium fluoride

dinitrogen oxide

phosphorous trichloride

hydrogen chloride

What do sodium ions have in common with chloride ions?

they both have the same sized charge

they are both cations

they are both anions

they both form covalent bonds

What is the arrangement of the bonds in diamond as shown in this structure?

tetrahedral - (4 bonds each 109.5 degrees apart)

Which of the following is the definition of an allotrope?

2 or more different physical forms in which an element exist

The same chemical formula but a different structure

Different numbers of neutrons but same protons

Different states of a compound

What is the formula for the compound sulfur hexachloride?

SCl6

What is the charge on group 1 metals?

1+

What is the suffix for all binary ionic compounds of representative elements?

-ide

Maitha claims that a single sodium ion and a single oxygen ion do not bond together to form a stable binary ionic compound. Is she correct? You must explain completely

Maitha is correct. The sum of the charges of the two ions must be zero in order for them to form a stable ionic compound.

What is the chemical formula for diamond?

C(s)

In the formation of the compound of sodium chloride

a sodium atom donates an electron to a chlorine atom

Covalent bonds take place between

two nonmetals

Which rule must be fulfilled by sharing or transferring electrons to create bonds in order for an element to be stable?

octet rule

What will the result be when a reaction between bismuth and fluorine takes place?

BiF3

Which pairs of words correctly completes the statement? Ionic compounds form when____ and _____ react.

metals ; nonmetals

Unknown element W has 2 valence electrons. Unknown element X has 7 valence electrons. Which formula shows the most likely outcome when elements W and X react?

WX2

What is the name of the compound Ni(NO3)2

Nickel (II) nitrate

What is the chemical formula for the compound barium bromide?

BaBr2

What is the name of the compound BaCl2

barium chloride

What is the sum of the charges in a compound?

0

A chemical formula includes the symbols of the elements in the compound and subscripts that indicate

the number of atoms or ions of each type

What is the metallic ion in the compound CuCl2?

Cu2+

Calcium (Ca) is in the second column of the periodic table and is classified as an alkaline earth metal. Which of the following formulas shows the ratio of a compound formed from calcium and iodine(I)?

CaI2

What is the formula for the cpm[ound formed when a potassium ion(K+) and a sulfide ion (S-2) unite?

K2S

What is the overall charge of the compound sodium chloride?

0

What is the chemical formula for calcium oxide?

CaO

What is the formula for the compound formed by magnesium cation (Mg+2) and a fluoride anion (F-)

MgF2

What is the formula for the compound formed when aluminum ions(Al 3+) and chloride ions (Cl -) unite?

AlCl3

Covalent compounds are formed when atoms

share valence electrons