Intermolecular Forces
Stoichiometry
Reactions
Energy
100

What is the difference between intermolecular forces and intramolecular forces?

Intermolecular forces are interactions between different molecules while Intramolecular forces are interactions within the same molecule.

100

What is the sum of all the coefficients when the following equation is balanced (lowest multiple whole numbers)?

NH3(g) + O2(g) -> NO(g) + H2O(g)

19 = 4NH3(g) + 5O2(g) -> 4NO(g) + 6H2O(g)

100

Which of the following are ionic compounds? Select all that apply.

  1. Sodium chloride

  2. Potassium Hydroxide

  3. H2O

  4. C5H12

  5. MgO

Sodium Chloride, Potassium Hydroxide, MgO

100

The following reaction is (exothermic or endothermic?): CH4(g) + 2O2(g) → CO2 + 2H2O(g) + energy (heat)

Exothermic

200

Two hydrogen atoms are bound by a covalent bond, which is the sharing of electrons

200

A 1.02g Magnesium supplement contains 25% Mg by mass. The Magnesium is present in the supplement as MgO(s) (molar mass 40.3 g/mol). How many grams of MgO(s) are in the magnesium supplement?

.423 g Mg

200

Which of the following is an example of a chemical change? (may be more than one): 

  1. Sugar dissolving in hot tea

  2. Burning firewood

  3. Metal rusting

  4. Boiling water

  5. An egg rotting

Burning firewood

Metal rusting

An egg rotting

200

Using enthalpies of formation, calculate the standard change in enthalpy for the thermite reaction: 

2Al(s) + Fe2O3(s) → Al2O3(s) + 2Fe(s)

(This reaction occurs when a mixture of powdered aluminum and iron(III) oxide is ignited with a magnesium fuse.)

∆Hf० (kJ/mol) Al2O3(s) = -1676

∆Hf० (kJ/mol) Fe2O3(s) = -826


-850 kJ

300

As a solid, the ionic elements can't move around. Dissolved in a liquid, ions are basically moving charges and can create a negative current.

300

Please write out the electron configuration for Aluminum (Al).

1s22s22p63s23p1

or 

[Ne] 3s23p1

300
  1. Which of the following influence the rate of a reaction? (there could be more than one)

    1. Surface area of reactant

    2. Vibes

    3. Temperature

    4. Catalysts

    5. Reactant concentration

Surface area of the reactant, Temperature, Catalysts, Reactant concentration

300

The enthalpy change (∆H) of a reaction gives the amount of heat energy released for (-∆H or +∆H?)  values or energy absorbed for (-∆H or +∆H?) values by a chemical reaction at constant pressure.

 The enthalpy change (∆H) of a reaction gives the amount of heat energy released for -∆H  values or energy absorbed for +∆H values by a chemical reaction at constant pressure.

400

Hydrogen bonds are the most powerful because of the permanent difference in electronegativity between H,N,O,F. Dipole dipole attractions are the same, but the difference may not be as severe. Dispersion forces are weak and happen between nonpolar substances.

400

If 15g of aluminum hydroxide is found in a single tablet, determine the theoretical yield of aluminum chloride that would form if you assume there was an excess amount of hydrochloric acid. Then, if 23g of aluminum chloride were measured in the products, calculate the percent yield.

 25.63g AlCl3,  89.74%

400

Determine the rate law and the value of the rate constant for the reaction at -10°C:

2NO(g) + Cl2(g) → 2NOCl(g)

Trial    [NO]o(mol/L)    [Cl2](mol/L)    Initial rate 

1               .10                .10                  .18

2               .10                .20                  .36

3               .20                .20                  1.45

 Rate=k[NO]2[Cl2]; k= 180 L2 mol-2 s-1

400

When 1 mole of methane (CH4) is burned at constant pressure, 890 kJ of energy is released as heat. Calculate ∆H for a process in which a 5.8 gram sample of methane is burned at constant pressure.

∆H= -320kJ

500

How does Photoelectron Spectroscopy work and why is it important?

Photoelectron spectrometers work by ionizing samples using high-energy radiation to eject electrons from their samples. It is important because it tells us the relative energies of electrons in atoms and molecules.

500

What volume of carbon dioxide gas is produced at STP by the decomposition of 0.150 g CaCO3 via the equation: CaCO3(s)→CaO(s)+CO2(g)?

.0336 L or 33.6 mL of CO2

500

.0048 mol of PH3 is consumed in a 2.0 L container during each second of the reaction. If the molecular equation for this reaction is 4PH3(g) → P4(g) + 6H2(g), which reactant is being produced/consumed the fastest?

  1. PH3

  2. P4

  3. H2

H2

500

Two forms of carbon are graphite, the soft, black, slippery material used in “lead” pencils and as a lubricant for locks, and diamond, the brilliant, hard gemstone. Using the enthalpies of combustion for graphite (-394 kJ/mol) and diamond (-396 kJ/mol), calculate ∆H for the conversion of graphite to diamond: Cgraphite → Cdiamond


∆H = 2 kJ

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