CHEM MC FINAL

Which of the following describes the gaseous state of mater

particles move randomly throughout the container

Which of the following describes an extensive property of gasoline

(B) a container can

Sterling silver can be produced by uniformly mixing gold in various amounts of silver. Sterling silver is an example of

a homogeneous mixture

An example of a chemical change is

propane gas burning in your store

how would you determine the density of an irregular shaped object?

D = M/V so measure the mass of the object using a balance. Then to find volume, fill a graduated cylinder with water and immerse the object in water. The amount of displaced water is the volume in cm^3 or mL

The following are some recorded temperatures. which is the lowest

freezing point of water, 273K

Which of the following pairs of molecules illustrates the law of multiple proportions

(a) PCl3 and PCl5

The existence of the electron, the negatively charged particles in atoms was demonstrated by

J.J Thompson

The time averaged distance between the centers of earth and the moon in 385000.6 km. which of the following is the correct way to express this number in scientific notation and significant figures?

(c) 3.850006 x 10^5

A student measured the diameter of a sphere and determined the average value. His measurements are 5.17cm, 5.16cm, 5.16cm, 5.17cm. If the true diameter is 6.18cm, what can be said about the student’s results?

It is precise but not accurate (h)

In covalent bonds, atoms share electrons

(b) to attain noble gas electron configurations

which of the following pairs of elements is most likely to form an ionic compound?

barium and chlorine

Given the lewis dot symbol for an unknown element, X. according to octet rule, this atom would most likely

gain two electrons to form an anion

Which of the following bonded atoms is the most polar?

CL-F OR F-N (pick D tho)

A nonpolar covalent bond results from the unequal sharing of a pair of electrons between atoms in a molecule

False

Consider the molecule below. Determine the molecular geometry at each of the 2 labeled carbons

(D) C1 = trigonal planar, C2 = tetrahedral

Describe a pi bond

side by side overlap of p orbitals

The number of pi bonds in the molecule below is

(D) 4

Draw the lewis structure for SO3. What is the hybridization on the S atom

sp2 (C)

One mole of O2 contains the same number of O atoms as

one mole of CO2 (c)

Which of the following compounds contains the highest H% by mass?

(g) H2O

In the balanced chemical equation 2 C + 02 → 2CO2

All of these are true (D)

When combining substances, you know that a reaction has taken place if

(I) any of the above occurs

Based on solubility rules, which of the following is expected to be insoluble in water?

(a) BaSO4

The reaction 2NaOH (aq) + MgCl2 → 2NaCl + Mg(OH)2 is best classified as an

(g) acid-base (?)

What is the net ionic equation for the neutralization reaction HF (a weak acid) + KOH → H2O + KF

(A) aq+aq = l

What is the mass of one molecule (molecular mass) of copper (II) nitrate, Cu(NO3)2

(c) 187.56 amu

The first law of thermodynamics

is a statement of conversation of energy (C)

An endothermic reaction causes the surroundings to

get colder (g)

For which of the following should the standard heat of formation be zero at 25C

(b) O2

which equation represents the standard enthalpy of formation of HgCl2 at 25C

(g) Hg(l) + Cl2(g) → HgCl2 (s) (LGS)

A system expands into a vacuum without gaining or losing heat. For this process

U = 0; internal energy does not change (C)

for an ideal gas, if the temperature of the gas is doubled at constant volume and number of moles. the pressure of the gas

(F) will not change

The student obtained experimental data and plotted it graphically but forgot to label the axes of the graph. How should the axes of the graph shown here be labeled?

(D) V and P (VP)

According to the Kinetic Molecular theory for an ideal gas

(D) fases are made up of tiny particles in constant chaotic motion

Real gases behave very closely to an ideal gas under conditions of

(H) low pressure and high temperature

A stoppered erlenmeyer flash, contains four different gases at STP which gas will effuse the fastest once we drill a hole on the stopper

(I) Ne

a scuba tank has a volume of 12 L. What volume of air at 1.0atm is required to fill the tank to a pressure of 150atm, assuming no change in temperature

(B) 1800L

Given the following data, calculate the enthalpy of combustion per mole of butane C4H10

(I) -2877.4 kJ

Using the VSEPR model, the molecular geometry of the central atom in BF3 is

(B) TRIGONAL PLANAR

Based on the molecular orbital diagram for He2 molecule?

(C) He2 does not exist

Give the approximate bond angle for a molecule with a linear shape

(B) 180

Consider the species O2-, O2, AND O2+. Which of these species will be paramagnetic?

(E) all three are magnetic