Chapter 1 MULTIPLE CHOICE QUESTIONS Topic: Atomic Orbitals 1. A) B) C) D) E) In quantum mechanics a node (nodal surface or plane) is: a place where Ψ is negative. a place where Ψ is positive. a place where Ψ = 0. a place where Ψ2 is large. a place where Ψ2 is negative. Ans: C Topic: Atomic Orbitals‚ Molecular Orbitals 2. When the 1s orbitals of two hydrogen atoms combine to form a hydrogen molecule‚ how many molecular orbitals are formed? A) 1 B) 2 C) 3 D) 4 E) 5 Ans:
Premium Molecule Oxygen Covalent bond
higher frequency in an IR spectrum? a. O or OH C=O > C-O b. N or NH C=N > C-N c. H or H C-H sp2 > C-H sp3 Callam 2/8 CHEM – 254 – WI -2009 2. What major IR absorptions are present above 1500 cm-1 for each compound? a. b. O sp3 C-H stretch 2950 C=O - ketone 1715 cm-1 cm-1 c. O sp3 C-H stretch 2950 cm-1 sp3 C-H stretch 2950 cm-1 sp2 C-H stretch 3100 cm-1 C=O - ketone 1715 cm-1 C=C alkene 1680 cm-1 O O d. e. f. OH sp3 C-H stretch 2950 sp C-H stretch 3310
Premium Oxygen Atom Molecule
centrifuge‚ the precipitate was settled and the supernate was discarded. 3.0 mL of distilled water and 10 drops of 0.10 M NaOH were added into each test tube. The test tubes were then prepared according to Table 1. Table 1. The reagents to be added for Cu(OH)2(s) equilibrium Test tube | Reagent to be added | 1 | 2.0 mL distilled water | 2 | 2.0 mL 1.0 M H2C2O4 solution | 3 | 2.0 mL water + pinch of Zn dust | 4 | 2.0 mL of 1.0 HNO3 | 5 | 2.0 mL of 6.0 M NH3 | 6 | 2.0 mL of 0.10 M Na3PO4 |
Premium Sodium chloride Sodium Chemical equilibrium
supposed to be Oh Boy you stand by me I’m forever yours faithfully Circus life under the big top world We all need the clowns to make us smile Through space and time Always another show Wondering where I am lost without you And being a part ain’t easy on this love affair Two strangers learn to fall in love again I get the joy of rediscovering you Oh girl you stand by me! I’m forever yours faithfully Oh oh oh oh oh oh oh oh oh oh oh oh oh oh oh oh faithfully
Premium 2006 singles Debut albums
reduced to give the corresponding alcohols when treated with LAH (Scheme 3). For the reduction of aldehydes and ketones‚ the reaction is generally performed in ether solvents at low temperature. O R or O R R’ R H LiAlH4 R OH or H OH R’ O Br Me LiAlH4 Et2O‚ -78 C Scheme 3 OH Br Me Mechanism The hydride from LAH is transferred to the carbonyl group to form alkoxy anion which then forms complex with aluminum (Scheme 4). Similarly‚ four hydride atoms are replaced by four alkoxy groups and
Premium Hydrogen Alcohol
categories; monosaccharides‚ disaccharides and polysaccharides (Table 1). Table 1. Structure of monosaccharides‚ disaccharides and polysaccharides Category Monosaccharide (made of 1 sugar molecule) Site fruit fruit‚ nectar milk H Structure OH OH H α-glucose Disaccharide (made of 2 monosaccharides joined together) Polysaccharide (made of many monosaccharides joined together) maltose = α-glucose + α-glucose sucrose = glucose + fructose lactose = glucose + galactose germinating seeds
Premium Glucose Starch Carbohydrate
reduction of CrO42–(aq) to Cr(OH)3(s) in a basic solution. a. CrO42–(aq) + 3 OH–(aq) + 3 e– Cr(OH)3(s) + 2 O2(g) b. CrO42–(aq) + 3 H+(aq) + 3 e– Cr(OH)3(s) c. CrO42–(aq) + 3 H+(aq) Cr(OH)3(s) + 2 e– d. CrO42–(aq) + 4 H2O( ) + 3 e– Cr(OH)3(s) + 5 OH–(aq) e. CrO42–(aq) + 3 OH–(aq) Cr(OH)3(s) + 2 O2(g) 4. Write a balanced chemical equation for the oxidation of Cd(s) by concentrated nitric acid‚ producing NO2(g) and Cd2+(aq). a. HNO3(aq) + Cd(s) Cd2+(aq) + NO2(g) + OH–(aq) b. 2 HNO3(aq) + Cd(s)
Premium Oxidizing agent Electrochemistry Hydrogen
tattooed in an arrow heart (hey‚ hey) And I know now‚ that I’m so down (hey‚ hey) Hey DON’T STOP- You’re like perfection‚ some kind of holiday You got me thinking that we could run away You want I’ll take you there‚ You tell me when and where‚ Oh oh oh oh But then I asked for your number‚ Said you don’t
Premium 2009 singles 2007 singles 2005 singles
Unknown 2 Scheme “ Fair game” ions Cations: Na+‚ K+‚ NH4+ ‚ Ca2+‚ Mg(OH2)62+ ‚ Al(OH2)63+ Anions: SO42-‚ HSO4-‚ NO3-‚ OH-‚ Cl-‚ CO32-‚ HCO3- Insoluble Compounds: Ca(OH)2‚ CaSO4•2H2O‚ CaCO3‚ MgCO3‚ Mg(OH)2 I. Describe Sample a. Quick description of sample. Ex: Phase‚ color‚ odor‚ crystalline‚ amorphous‚ gel-like‚ powdery‚ etc. II. Flame Test a. Part 1 i. Orange Flame: Na+ is present. K+ ‚ NH4+ ‚ Ca2+‚ Mg(OH2)62 ‚ Al(OH2)63+ may also be present. ii. Purple Flame: K+ is present (no Na+
Premium Ion Chemistry Atom
everyone. Oh‚ when will they ever learn? Oh‚ when will they ever learn? Where have all the young girls gone‚ long time passing? Where have all the young girls gone‚ long time ago? Where have all the young girls gone? Gone for husbands everyone. Oh‚ when will they ever learn? Oh‚ when will they ever learn? Where have all the husbands gone‚ long time passing? Where have all the husbands gone‚ long time ago? Where have all the husbands gone? Gone for soldiers everyone Oh‚ when will
Premium World War II Vietnam War Army