Arrange the following three types of electromagnetic radiation- visible light, X-rays, microwaves, in order of increasing wavelength.
What is X-rays < visible < microwaves
100
The negative ion F- has the same electronic configuration as the positive ion
a)Ca 2+
b) Li +
c) Mg 2+
d) K+
e) Sc 3+
What is c) Mg 2+ ?
100
Draw the best VSEPR Lewis structure for OF2. What is the hybridization on the O atom?
What is sp3 ?
100
List the number of sigma bonds and pi bonds in a triple bond.
What is 1 sigma, 2 pi ?
100
A mixture of 16 g of He, 21 g of N2, and 16 g of O2 at 25 degrees C is in a 75 L container. What are the mole fractions of each of the three gases?
What is .762, .143, .0952
200
Which of the following transitions (in a hydrogen atom) represent emission of the longest wavelength photon?
a) n=2 to n=1
b)n=5 to n=4
c) n=4 to n=3
d)n=3 to n=1
What is b) n=5 to n=4 ?
Transitions between orbitals that are further apart in energy produce light that is higher in energy, and therefore shorter in wavelength than transitions between orbitals that are closer together.
200
Which of the following pairs of species are isoelectronic?
a) Ne, K+
b) Rb, Cs
c) Cl-, S 2-
d) Na, Al 3+
e)S 2-, Se 2-
What is c) Cl-, S 2- ?
200
What is the molecular geomtry around a central atom that is sp3 hybridized and has one lone electron-pair?
What is trigonal-pyramidal?
200
Which of the following is paramagnetic?
a)H2-
b)H2
c)C2
d)Li2
e)B2 2+
What is H2 - ?
200
A sample of gas ocupies 3.24 liters at 25 degrees C and 734 torr. Whsat volume does it occupy at STP?
What is 2.87 L ?
300
What type of orbital is designated n=3, l=2, ml= -1?
What is 3d?
300
Arrange the following elements in order of decreasing atomic radii: Pb, P, Cl, F, Si
What is Pb > Si > P > Cl > F
300
A molecule containing a central atom with sp3d2 hybridization has a __________ electron geometry.
What is octahedral?
300
How many of the following molecules have a sp2 hybridization on the central atom?
HCN
SO2
OCl2
XeCl2
What is 1?
300
Calculate the density of O2 gas (in g/L) at 1.22 atm and 25 degrees C.
What is 1.60 g/L ?
400
When an electron of an excited hydrogen atom falls from level n=3 to level n=2, what is the frequency (in s^-1) of the light emitted?
What is 4.57 x 10^14 s^-1 ?
400
Arrange the following set of ions in order of increasing ionic radii: Ca 2+, Cl-, K+, P 3-, S 2-
What is Ca 2+ < K + < Cl- < S 2-
400
Which molecule or compound below contains a pure covalent bond?
a) Li2CO3
b) SCl6
c) Cl2
d) PF3
e) NaCl
explain why the others are not pure covalent
What is Cl2 ?
400
According to the molecular orbital theory, which of the following species is least likely to exist?
a) H2+
b) H2
c) C2 2-
d)Li2 2-
e) B2 +
What is Li2 2- ?
400
A denitist has a 5.00 L cylinder of "laughing gas," N2O, at 20 atm and 25 degrees C. What mass of gas is contained in it?
What is 180 g ?
500
Calculate the energy (J/photon) of a photon of wavelength 4.50 x 10^-8 m.
What is 4.42 x 10^-18 J ?
500
Arrange the following elements in order of increasing values of electron affinity i.e. most negative to least negative: Cl, Se, S, Cs, Rb, Te
What is Cl < S < Se < Te < Rb < Cs
500
Draw the best Lewis structure for H3O+. What are the formal charges on the O and H atoms?
What is (1,0) ?
500
Place the following in order of increasing density at STP
N2, NH3, N2O4, He
What is He < NH3 < N2 < N2O4 ?
500
A gaseous compound has the empirical formula CH2. Its density is 0.465 g/L at 0.465 atm and 373 K. What is the molecular formula of the gas? (R= 0.08207L*atm/mol*K)