Second exam

1-Which of the following pressure units has the largest value? Second exam 1-Which of the following pressure units has the largest value?  a)765 torr b) 1.00 atm c) 595 mmHg d) 167 Pa a- 765/760 = 1.007 atm b- 1 atm c- 595/760=0.78 atm d- 167 / 1.01 x 105 = 0.0017 atm

1-Which of the following pressure units has the largest value? Second exam 1-Which of the following pressure units has the largest value?  a)765 torr b) 1.00 atm c) 595 mmHg d) 167 Pa 2- A sample of oxygen occupies 6.33 liters under a pressure of 1240 mmHg at 25°C. What volume would it occupy at 25°C if the pressure was decreased to 0.960 atm? a) 23.6 L b) 12.7 L c) 32.1 L d) 10.76 L V1= 6.33 L , P1= 1240 mmHg = 1240 / 760= 1.63 atm, P2=0.96 atm, V2= ?, T1=T2 P1 V1 = P2 V2 1.63 x 6.33 = 0.96 x V2 V2 = 10.33 / 0.96 = 10.76 L

1-Which of the following pressure units has the largest value? Second exam 1-Which of the following pressure units has the largest value?  a)765 torr b) 1.00 atm c) 595 mmHg d) 167 Pa 2- A sample of oxygen occupies 6.33 liters under a pressure of 1240 mmHg at 25°C. What volume would it occupy at 25°C if the pressure was decreased to 0.960 atm? a) 23.6 L b) 12.7 L c) 32.1 L d) 10.76 L 3- What is the pressure of 3.45×10-3 mol gas in a 0.1L flask at 21.2°C?  a) 0.99 atm b) 0.83 atm c) 0.197 atm d) 0.5 atm n= 3.45×10-3 mole, T= 21.2 °C= 21.2+273=294.2 K, V= 0.1L, P= ? PV=nRT P= nRT/V = 3.45×10-3 x 0.082 x 294.2 / 0.1 = 0.83 atm

1-Which of the following pressure units has the largest value? Second exam 1-Which of the following pressure units has the largest value?  a)765 torr b) 1.00 atm c) 595 mmHg d) 167 Pa 2- A sample of oxygen occupies 6.33 liters under a pressure of 1240 mmHg at 25°C. What volume would it occupy at 25°C if the pressure was decreased to 0.960 atm? a) 23.6 L b) 12.7 L c) 32.1 L d) 10.76 L 3- What is the pressure of 3.45×10-3 mol gas in a 0.1L flask at 21.2°C?  a) 0.99 atm b) 0.83 atm c) 0.197 atm d) 0.5 atm 4- What is the mass of nitrogen gas (M=28 g/mol) in 500 mL flask at STP? a) 0.625 g b) 0.750 g c) 0.875 g d) 1.125 g  

V= 500 ml= 500/1000= 0.5L, T= 273K, P= 1 atm, Mwt= 28 g/mol PV= nRT Second exam 4- What is the mass of nitrogen gas (M=28 g/mol) in 500 mL flask at STP? a) 0.625 g b) 0.750 g c) 0.875 g d) 1.125 g V= 500 ml= 500/1000= 0.5L, T= 273K, P= 1 atm, Mwt= 28 g/mol PV= nRT n= PV/RT = 1 x 0.5 /( 0.082 x 273) = 0. 022 mol Mass = n x molar mass = 0.022 x 28 = 0.625 g  

1-Which of the following pressure units has the largest value? Second exam 1-Which of the following pressure units has the largest value?  a)765 torr b) 1.00 atm c) 595 mmHg d) 167 Pa 2- A sample of oxygen occupies 6.33 liters under a pressure of 1240 mmHg at 25°C. What volume would it occupy at 25°C if the pressure was decreased to 0.960 atm? a) 23.6 L b) 12.7 L c) 32.1 L d) 10.76 L 3- What is the pressure of 3.45×10-3 mol gas in a 0.1L flask at 21.2°C?  a) 0.99 atm b) 0.83 atm c) 0.197 atm d) 0.5 atm 4- What is the mass of nitrogen gas (M=28 g/mol) in 500 mL flask at STP? a) 0.625 g b) 0.750 g c) 0.875 g d) 1.125 g  

5- What is the density of oxygen gas (M= 32 g/mol) at STP? Second exam 5- What is the density of oxygen gas (M= 32 g/mol) at STP? a) 1.64 g/L b) 2.91 g/L c) 1.43 g/L d) 1.15 g/L Mwt = 32 g/mol, T=273 K, P= 1 atm,

5- What is the density of oxygen gas (M= 32 g/mol) at STP? Second exam 5- What is the density of oxygen gas (M= 32 g/mol) at STP? a) 1.64 g/L b) 2.91 g/L c) 1.43 g/L d) 1.15 g/L 6- A mixture of gases contains 6.0 mol of H2 gas and 2.5 mol of He gas. If the total pressure is 1.15 atm, calculate the partial pressure of the H2 gas.  a) 1.06 atm b) 0.812 atm c) 2.12 atm d) 1.41 atm nH2= 6 mol, nHe = 2.5 mol, PT = 1.15 atm, PH2 = ?

5- What is the density of oxygen gas (M= 32 g/mol) at STP? Second exam 5- What is the density of oxygen gas (M= 32 g/mol) at STP? a) 1.64 g/L b) 2.91 g/L c) 1.43 g/L d) 1.15 g/L 6- A mixture of gases contains 6.0 mol of H2 gas and 2.5 mol of He gas. If the total pressure is 1.15 atm, calculate the partial pressure of the H2 gas.  a) 1.06 atm b) 0.812 atm c) 2.12 atm d) 1.41 atm 7- A mixture of 3 mol N2 gas and 4 mol O2 are in 2 L flask at 300 K, what is the total pressure? a) 57.4 atm b) 86.1 atm c) 43.05 atm d) 34.44 atm nN2= 3 mol, nO2 = 4 mol, V = 2 L, T= 300K, PT = ? Where n = nA + nB

5- What is the density of oxygen gas (M= 32 g/mol) at STP? Second exam 5- What is the density of oxygen gas (M= 32 g/mol) at STP? a) 1.64 g/L b) 2.91 g/L c) 1.43 g/L d) 1.15 g/L 6- A mixture of gases contains 6.0 mol of H2 gas and 2.5 mol of He gas. If the total pressure is 1.15 atm, calculate the partial pressure of the H2 gas.  a) 1.06 atm b) 0.812 atm c) 2.12 atm d) 1.41 atm 7- A mixture of 3 mol N2 gas and 4 mol O2 are in 2 L flask at 300 K, what is the total pressure? a) 57.4 atm b) 86.1 atm c) 43.05 atm d) 34.44 atm 8- What is the wavelength (λ) of radiation that has a frequency (υ) of 1.0 x 1014 Hz? a) 5x10-3 cm b) 1x10-4 cm c) 3x10-4 cm d) 1x10-6 cm

a) 5x10-3 cm b) 1x10-4 cm c) 3x10-4 cm d) 1x10-6 cm Second exam 8- What is the wavelength (λ) of radiation that has a frequency (υ) of 1.0 x 1014 Hz? a) 5x10-3 cm b) 1x10-4 cm c) 3x10-4 cm d) 1x10-6 cm V= 1.0  1014 s-1 , λ=? c = λν λ=c/v = 3x108 /(1.0  1014 ) = 3.0 x10-6 m = 3.0 X10-4 cm

5- What is the density of oxygen gas (M= 32 g/mol) at STP? Second exam 5- What is the density of oxygen gas (M= 32 g/mol) at STP? a) 1.64 g/L b) 2.91 g/L c) 1.43 g/L d) 1.15 g/L 6- A mixture of gases contains 6.0 mol of H2 gas and 2.5 mol of He gas. If the total pressure is 1.15 atm, calculate the partial pressure of the H2 gas.  a) 1.06 atm b) 0.812 atm c) 2.12 atm d) 1.41 atm 7- A mixture of 3 mol N2 gas and 4 mol O2 are in 2 L flask at 300 K, what is the total pressure? a) 57.4 atm b) 86.1 atm c) 43.05 atm d) 34.44 atm 8- What is the wavelength (λ) of radiation that has a frequency (υ) of 1.0 x 1014 Hz? a) 5x10-3 cm b) 1x10-4 cm c) 3x10-4 cm d) 1x10-6 cm

Second exam 9- Calculate the volume of O2 (in L) required for the complete combustion of 7.64 L of C2H2 measured at the same temperature and pressure? a) 19.1 L b) 9.1L c) 21.6L d) 14.1 L From equation 2 mol C2H2 5 mol O2 2L C2H2 5L O2 7.64 L C2H2 ? L O2 5 x 7.64 = 2 x ? Volume of O2 = 5 X 7.64 / 2 = 19.1 L X

Second exam 9- Calculate the volume of O2 (in L) required for the complete combustion of 7.64 L of C2H2 measured at the same temperature and pressure? a) 19.1 L b) 9.1L c) 21.6L d) 14.1 L 10-If the frequency (υ) of radiation is 1.00 x 108 Hz, what is the energy (E) of this radiation? a) 6.63 x 10-26 J b) 6.63 x 10-34 J c) 6.63 x 10-42 J d) 6.63 kJ E= 6.626 x 10-34 x 1 X 108 = 6.626 x 10-26

Second exam 9- Calculate the volume of O2 (in L) required for the complete combustion of 7.64 L of C2H2 measured at the same temperature and pressure? a) 19.1 L b) 9.1L c) 21.6L d) 14.1 L 10- If the frequency (υ) of radiation is 1.00 x 108 Hz, what is the energy (E) of this radiation? a) 6.63 x 10-26 J b) 6.63 x 10-34 J c) 6.63 x 10-42 J d) 6.63 kJ 11- What is the energy of radiation after transition of an electron from n = 3 to n = 2 in the hydrogen atom? (The Rydberg constant for H atom = 2.18  10-18 J) a) 3.03 x 10-17 J b) 3.03  10-18 J c) 3.03  10-19 J d) 2.18  10-15 J

Second exam 11- What is the energy of radiation after transition of an electron from n = 3 to n = 2 in the hydrogen atom? (The Rydberg constant for H atom = 2.18  10-18 J) a) 3.03 x 10-17 J b) 3.03  10-18 J c) 3.03  10-19 J d) 2.18  10-15 J

Second exam 9- Calculate the volume of O2 (in L) required for the complete combustion of 7.64 L of C2H2 measured at the same temperature and pressure? a) 19.1 L b) 9.1L c) 21.6L d) 14.1 L 10- If the frequency (υ) of radiation is 1.00 x 108 Hz, what is the energy (E) of this radiation? a) 6.63 x 10-26 J b) 6.63 x 10-34 J c) 6.63 x 10-42 J d) 6.63 kJ 11- What is the energy of radiation after transition of an electron from n = 3 to n = 2 in the hydrogen atom? (The Rydberg constant for H atom = 2.18  10-18 J) a) 3.03 x 10-17 J b) 3.03  10-18 J c) 3.03  10-19 J d) 2.18  10-15 J

a) from n = 1 to n = 4 b) from n = 1 to n = 2 Second exam 12- Which of the following electron transitions would absorb the lowest energy by the hydrogen atom? a) from n = 1 to n = 4 b) from n = 1 to n = 2 c) from n = 1 to n = 7 d) from n = 1 to n = 6 13- Calculate the wavelength associated with a beam of neutrons moving at 7.0 x 102 m/s? (The mass of a neutron is 1.675 x 10-27 kg). a) 0.565 nm b) 1.318 nm c) 0.747 nm d) 0.439 nm m= 1.675 x 10-27 kg, u= 7.0 x 102 m/s

a) from n = 1 to n = 4 b) from n = 1 to n = 2 Second exam 12- Which of the following electron transitions would absorb the lowest energy by the hydrogen atom? a) from n = 1 to n = 4 b) from n = 1 to n = 2 c) from n = 1 to n = 7 d) from n = 1 to n = 6 13- Calculate the wavelength associated with a beam of neutrons moving at 7.0 x 102 m/s? (The mass of a neutron is 1.675 x 10-27 kg). a) 0.565 nm b) 1.318 nm c) 0.747 nm d) 0.439 nm 14- The volume of a sample of nitrogen is 7.20 liters at 35°C and 0.970 atm. What volume will it occupy at STP? a) 8.17 L b) 5.16 L c) 4.30 L d) 6.19 L 

Second exam 14- The volume of a sample of nitrogen is 7.20 liters at 35°C and 0.970 atm. What volume will it occupy at STP? a) 8.17 L b) 5.16 L c) 4.30 L d) 6.19 L  V1=7.2 L, T1= 35C = 35+273=308K, P1= 0.970atm, P2= 1atm, T1=273 K, V2=?

a) from n = 1 to n = 4 b) from n = 1 to n = 2 Second exam 12- Which of the following electron transitions would absorb the lowest energy by the hydrogen atom? a) from n = 1 to n = 4 b) from n = 1 to n = 2 c) from n = 1 to n = 7 d) from n = 1 to n = 6 13- Calculate the wavelength associated with a beam of neutrons moving at 7.0 x 102 m/s? (The mass of a neutron is 1.675 x 10-27 kg). a) 0.565 nm b) 1.318 nm c) 0.747 nm d) 0.439 nm 14- The volume of a sample of nitrogen is 7.20 liters at 35°C and 0.970 atm. What volume will it occupy at STP? a) 8.17 L b) 5.16 L c) 4.30 L d) 6.19 L 

a) n = 2, l = 2, ml = –2, –1, 0, 1, 2 b) n = 2, l = 1, ml = 0 Second exam 15- Give the values of the quantum numbers (n, l and ml) associated with the 2p subshell? a) n = 2, l = 2, ml = –2, –1, 0, 1, 2 b) n = 2, l = 1, ml = 0 c) n = 2, l = 1, ml = 1 d) n = 2, l = 1, ml = –1, 0, 1 16- The electron configuration of a neutral atom is 1s2 2s2 2p6 3s2. Name the element? a) Si b) Na c)Mg d) Al 1s2 2s2 2p6 3s2 = 2+2+6+2=12=Mg

a) n = 2, l = 2, ml = –2, –1, 0, 1, 2 b) n = 2, l = 1, ml = 0 Second exam 15- Give the values of the quantum numbers (n, l and ml) associated with the 2p subshell? a) n = 2, l = 2, ml = –2, –1, 0, 1, 2 b) n = 2, l = 1, ml = 0 c) n = 2, l = 1, ml = 1 d) n = 2, l = 1, ml = –1, 0, 1 16- The electron configuration of a neutral atom is 1s2 2s2 2p6 3s2. Name the element? a) Si b) Na c)Mg d) Al 17- A ground-state atom of zinc (Zn) has ___ unpaired electrons and is _____. a) 0, paramagnetic b) 1, paramagnetic c) 2, paramagnetic d) 0, diamagnetic

a) 0, paramagnetic b) 1, paramagnetic Second exam 17- A ground-state atom of zinc (Zn) has ___ unpaired electrons and is _____. a) 0, paramagnetic b) 1, paramagnetic c) 2, paramagnetic d) 0, diamagnetic Zn=30e [Ar] 4s2 3d10 4s2 3d10

a) n = 2, l = 2, ml = –2, –1, 0, 1, 2 b) n = 2, l = 1, ml = 0 Second exam 15- Give the values of the quantum numbers (n, l and ml) associated with the 2p subshell? a) n = 2, l = 2, ml = –2, –1, 0, 1, 2 b) n = 2, l = 1, ml = 0 c) n = 2, l = 1, ml = 1 d) n = 2, l = 1, ml = –1, 0, 1 16- The electron configuration of a neutral atom is 1s2 2s2 2p6 3s2. Name the element? a) Si b) Na c)Mg d) Al 17- A ground-state atom of zinc (Zn) has ___ unpaired electrons and is _____. a) 0, paramagnetic b) 1, paramagnetic c) 2, paramagnetic d) 0, diamagnetic

a) Noble gases b) Halogens c) Alkali metals d) Alkaline earth metals Second exam 18- The elements having ns1 configuration in their outermost shell are: a) Noble gases b) Halogens c) Alkali metals d) Alkaline earth metals 19- O-2 is isoelectronic with : a) F– b) K+ c) Cl- d) Ar O-2 = 10e F- = 10, Cl- =18, K +=20, Ar=18

a) Noble gases b) Halogens c) Alkali metals d) Alkaline earth metals Second exam 18- The elements having ns1 configuration in their outermost shell are: a) Noble gases b) Halogens c) Alkali metals d) Alkaline earth metals 19- O-2 is isoelectronic with : a) F– b) K+ c) Cl- d) Ar 20- Electron affinity is highest for : a) Cl b) I c) S d) Br

20- Electron affinity is highest for : a) Cl b) I c) S d) Br Second exam 20- Electron affinity is highest for : a) Cl b) I c) S d) Br

a) Noble gases b) Halogens c) Alkali metals d) Alkaline earth metals Second exam 18- The elements having ns1 configuration in their outermost shell are: a) Noble gases b) Halogens c) Alkali metals d) Alkaline earth metals 19- O-2 is isoelectronic with : a) F– b) K+ c) Cl- d) Ar 20- Electron affinity is highest for : a) Cl b) I c) S d) Br 21- The electron configuration of V is: a) [Ar]4s24p3 b) [Kr]4s23d3 c) [Ar] 4s23d3 d) [Kr]4s24p3

22- Which of the following will form an ionic bond? Second exam 22- Which of the following will form an ionic bond? a) Mg and F b) Si and O c) C and O d) Cl and O 23- Pick out the correct statement from the following: a) Alkali metals have the lowest ionization energy b) Alkali metals have the highest ionization energy c) Halogens have the lowest ionization energy d) Inert gases have the lowest ionization energy 24- According to Lewis's theory, a covalent bond is formed by the: a) Transfer of electrons b) Sharing of electrons c) partial transfer of electrons d) Donation of electrons

25- How many total valance electrons are available in CO2 ? Second exam 25- How many total valance electrons are available in CO2 ? a) 10 b) 18 c) 16 d) 24 To answer this question and the following 3 questions we have to draw lewis structure Step 1 – C is less electronegative than O, put C in center Step 2 – Count valence electrons C - 4 (3s23p2) and O - 6 (2s22p4) 4+ (2 x 6) = 16 valence electrons Step 3 – Draw single bonds between C and O atoms and complete octets on C and O atoms. Step 4 - Check, are # of e- in structure equal to number of valence e- ? 2 single bonds (2x2) + 8 lone pairs (8x2) = 20 valence electrons Step 5 - Too many electrons, form double bond and re-check # of e- O C

25- How many total valance electrons are available in CO2 ? Second exam 25- How many total valance electrons are available in CO2 ? a) 10 b) 18 c) 16 d) 24 26- How many lone pairs of electrons are in CO2? a) 1 b) 4 c) 2 d) 0 27- How many resonance structures are there in CO2? a) 3 b) 2 c)1 d) 0 O C O C O C

25- How many total valance electrons are available in CO2 ? Second exam 25- How many total valance electrons are available in CO2 ? a) 10 b) 18 c) 16 d) 24 26- How many lone pairs of electrons are in CO2? a) 1 b) 4 c) 2 d) 0 27- How many resonance structures are there in CO2? a) 3 b) 2 c)1 d) 0 28- The formal charge on the carbon atom in CO2? a) +1 b) 0 c) -1 d) +2

( ) - 28- The formal charge on the carbon atom in CO2? Second exam 28- The formal charge on the carbon atom in CO2? a) +1 b) 0 c) -1 d) +2 O C 4 - - ½ (8) = 0 formal charge on an atom in a Lewis structure = 1 2 total number of bonding electrons ( ) total number of valence electrons in the free atom - total number of nonbonding electrons

25- How many total valance electrons are available in CO2 ? Second exam 25- How many total valance electrons are available in CO2 ? a) 10 b) 18 c) 16 d) 24 26- How many lone pairs of electrons are in CO2? a) 1 b) 4 c) 2 d) 0 27- How many resonance structures are there in CO2? a) 3 b) 2 c)1 d) 0 28- The formal charge on the carbon atom in CO2? a) +1 b) 0 c) -1 d) +2

Total number of orbital = n2 = 32 = 9 Second exam 29- What is the total number of sub-orbital associated with the principal quantum number n = 3? a) 3 b) 16 c) 9 d) 2 Total number of orbital = n2 = 32 = 9

30- Order the following according to increasing atomic radius. Second exam 29- What is the total number of sub-orbital associated with the principal quantum number n = 3? a) 3 b) 16 c) 9 d) 2 30- Order the following according to increasing atomic radius. N Be Mg C O B a) N > O > Mg > Be > C > B b) O < N < C < B < Be < Mg c) Mg< Be < B < C < N < O d) Be > Mg > B > C > N > O

30- Order the following according to increasing atomic radius. Second exam 30- Order the following according to increasing atomic radius. N Be Mg C O B a) N > O > Mg > Be > C > B b) O < N < C < B < Be < Mg c) Mg< Be < B < C < N < O d) Be > Mg > B > C > N > O

30- Order the following according to increasing atomic radius. Second exam 29- What is the total number of sub-orbital associated with the principal quantum number n = 3? a) 3 b) 16 c) 9 d) 2 30- Order the following according to increasing atomic radius. N Be Mg C O B a) N > O > Mg > Be > C > B b) O < N < C < B < Be < Mg c) Mg< Be < B < C < N < O d) Be > Mg > B > C > N > O

Thank you for listening