Swiggity Swaggity Chemistry Quarterly

1 Which of the following statements is TRUE?

(ALL THE ABOVE: the emission spectrum of a particular element is always the same and can be used to identify the element, part of Bohr model proposed that electrons in the hydrogen atom are located in "stationary states" or particular orbits around the nucleus, the uncertainty principle states that we can never know both the exact location and speed of an electron, an orbital is the volume in which we are most likely to find an electron)

Which of the following particulate diagrams best shows the formation of water vapor from hydrogen gas and oxygen gas in a rigid container at 125 degrees C?

(the diagram with 3 O2 molecules and 6 H2 molecules)

A bomb calorimeter has a heat capacity of 2.47 kJ/K. When a 0.111-g sample of ethylene (C2H4)was burned in this calorimeter, the temperature increased by 2.26 K. Calculate the energy of combustion for one mole of ethylene.

-1.41 x 10^3 kJ/mol

Consider the following processes: Calculate Hrxn for: CE+3D

-20 kJ/mol

The de Broglie wavelength of an electron with a velocity of 6.00E6 m/s is ____ m. The mass of the electron is 9.11E-28.

1.21E-10

It is possible to determine the ionization energy for hydrogen using the Bohr equation. Calculate the Ionization energy (in jK) for a mole of hydrogen atoms, making the assumption that ionization is the transition from n=1 to n= infinity.

1.31E3

How many molecules are in 2.5 mol of SO2?

1.51 x 10^24 atoms

A syringe contains 589 mL of CO at 325 K and 1.2 atm pressure. A second syringe contains 473 mL of N2at 298 K and 2.6 atm. What is the fina; pressure if the contents of these two syringes are injected into a 1.00 L container at STP?

1.7 atm

Silver has an atomic mass of 107.868 amu. The Ag-109 isotope (108.905 amu) is 48.16%. What is the amu of the other isotope?

106.905 amu

Determine the longest wavelength of light required to remove an electron from a sample of potassium metal, if the binding energy for an electron in K is 1.76E3.

147nm

Determine the end (final) value of n in a hydrogen atom transition, if the electron starts in n=4 and the atom emits a photon of light with a wavelength?

2

Beaker X and beaker Y each contain 1.0 L of solution, as shown above. A student combines the solutions by pouring them into a larger, previously empty beaker Z and observes the formation of a white precipitate. Assuming that volumes are additive, which of the following sets of solutions could be represented by the diagram above?

2.0 M AgNO3 1.0 M MgCl2 0.50M Mg(NO3)2 and AgCl(s)

If the melting point of vanadium metal is 1910 degrees Celcius, what is its melting point in Kelvin?

2183 K

Which of the following is the balanced net-ionic equation for the reaction between Li(s) and water?

2Li(s)+2H2O(l)2Li+(aq)+2OH-(aq)+H2(g)

Using the following equation for the combustion of octane, calculate the amount of grams of carbon dioxide formed from 100.0 g of octane. The molar mass of octane is 114.33 g/mole. The molar mass of carbon dioxide is 44.0095 g/mole. 2 C8H18+25 O216 CO2+18 H2O Hrxn=-11018 kJ

307.9 g

What answer should be reported, with the correct number of significant figures, for the following calculations?

4.57

The mole fraction of oxygen in dry air near sea level is 0.20948. The concentration of oxygen is _____ molecules per liter, assuming an atmosphere pressure of 739 torr and a temperature of 29.5 C?

4.93 x 10^21

How many photons are contained in a flash of green light (525nm) that contains 189 kJ of energy?

4.99E23

What volume of benzene C6H6, d=0.88 g/mL, molar mass=78.11 g/mol)is required to produce 1.5103kJ of heat according to the following reaction? 2 C6H6(l)+15 O2(g)12 CO2(g)+6 H2O(g) Hrxn=-6278 kJ

42 mL

What pressure would a gas mixture in a 10.0L tank exert fi it were composed of 48.5 g He and 94.6g CO2 at 398 K?

46.6 atm

In which orbital below would an electron (on average) be farthest from the nucleus?

4f

How many millimeters of ozone gas at 25.0 degrees and 1.00 atm pressure are needed to react with 45.00mL of 0.100 M aqueous solution of KI according to the chemical equation shown? O3 +2I-+H2OO2+I2+2 OH-

55.0 mL

Calculate the frequency of the green light emitted by a hydrogen atom with a wavelength of 486.1nm.

6.17E14

A hot iron ball is dropped into a 200. G sample of water initially 50C. If 8.4 kJ of heat is transferred from the ball to the water, what is the final temperature of the water? (The specific heat of water is 4.2 (J/g*C)

60*C

For a hydrogen atom, which electron transition would result in the emission of a photon with the highest energy?

6p-->4s

The action of some commercial drain cleaners is based on the following reaction: 2NaOH+2 Al+6H2O2 NaAl(OH)4+3 H2What is the volume of H_2 Gas formed at STP when 6.32 g of Al reacts with excess NaOH

7.87 L

Determine the shortest frequency of light required to move an electron from a sample of Ti metal, if the binding energy of titanium is 3.14E3 kJ/mol.

7.87E15

A student is preparing to perform a series of calorimetry experiments. She first wishes to determine the calorimeter constant (Ccal)for her coffee cup calorimeter. She pours a 50.0 mL sample of water at 345 K into the calorimeter containing a 50.0 mL sample of water at 298 K. She carefully records the final temperature of the water as 317 K. What is the value of (Ccal)for the calorimeter?

99 J/K

Determine the name for H2CO3?

Carbonic Acid

The experimental apparatus represented above is used to demonstrate the rates at which gases diffuse. When the cotton balls are placed in the ends of a tube at the same time ,the gases diffuse From each end and meet somewhere in between, where they react to form a white solid. Whivh of the following combinations will produce a solid closest to the center of the tube?

HCl and CH3NH2

If two electrons in the same atom have the same value of "l," they are

In the same sublevel, but not necessarily the same level.

When a hydrate of Na2CO3 is heated until all the water is removed, it loses 54.3% of its mass. The formula of the hydrate is

Na2CO3 7H2O

Which of the following statements correctly describes the signs of q and w for the following exothermic process at P = 1 atm and T = 370 K? H2O(g)H2O(l)

Q is negative, W is positive

Two flexible containers for gases are at the same temperature and pressure. One holds 0.50 gam of hydrogen and the other holds 8.0 grams of oxygen. Which of the following statements regarding these gas samples is FALSE?

The average speed

A 1.0 g sample of a cashew was burned in a calorimeter containing 1000. G of water, and the temperature of the water changed from 20.0*C to 25.0*C. In another experiment, a 3.0 g sample of a marshmallow was burned in a calorimeter containing 2000. g water, and the temperature of the water changed from 25.0*C to 30.0*C. Based on the data, which of the following can be concluded about the energy content for 1.0 g of each of the two substances? (The specific heat of water is 4.2 J/(g*C)

The combustion of 1.0 g of cashew releases more energy than the combustion of 1.0 g of marshmallow

The heating curve for a sample of pure ethanol is provided above. The temperature was recorded as a 50.0 g sample of solid ethanol was heated at a constant rate. Which of the following explains why the slope of segment T is a greater than the slope of segment R?

The heat of vaporization of ethanol is greater than the heat of fusion of ethanol

Which of the following statements is TRUE?

The magnetic quantum number (ml) describes the orientation of the orbital.

When a sample of oxygen gas in a closed container of constant volume is heated until its absolute volume is heated until its absolute temperature is doubled, which of the following is also doubled?

The pressure of the gas

On a cold winter day, a steel metal fence post feels colder than a wooden fence post of identical size because:

The specific heat capacity of steel is lower than the specific heat capacity of wood

A compound is heated to produce a gas whose molecular weight is to be determined. The gas is collected by displacing water in a water-filled flask inverted in a trough of water. Which of the following is necessary to calculate the molecular weight of the gas, but does NOT need to be measured during the experiment?

Vapor pressure of the water

When the actual gas volume is greater than the volume predicted by the ideal gas law, the explanation lies in the fact that the ideal gas law does NOT include a factor of molecular

Volume`

What are the possible values of n and ml for an electron in a 3d orbital?

n=3 and ml=2

Which of the following transitions (in a hydrogen atom) represent emission of the longest wavelength photon?

n=5 to n=4

Which of the following diagrams best depicts an alloy of Ni and B?

the one with the big and small particles