Chemistry Questions and Answers January 10, 2020

How many milliliters of 0.2 M Mg(OH) 2 (aq) are required to titrate 25 ml 0.3 M HC 3 H 5 O 2 (aq)? (Hint: What is the net reaction?)

Draw the last half of the mechanism for the aldol condensation reaction of Benzil and 1,3 Diphenyl acetone to form TPCPD below. Begin the mechanism from the intermediate specified below. (20) triethylene glycol, 110C Intermediate (begin mechanism to make 5membered ring TPCPD) Ph. Ph Ph, Ph

Consider the following reaction H (ag) NaO (ag) 2 () NaCI (aq) When 100 mL each of 1.0 molL hydrochloric acid and sodium hydroxide are mixed in a coffee cup calorimeter, the temperature of the solution rises from 21.0 C to 29.5 C. You may have to refer to notes from previous units to complete this question. Please show all working and state all

Provide the starting material and final product in this 3 step synthesis below. ,I. CH,MgBr (1 eq) O, (ozone) 2. H,0

Draw the major product of the following reaction. mayl H3C H HO C10H140

Draw the mechanism for the synthesis of the chalcone product below. Include and label the formation of the ketol intermediate, and the ElcB mechanism in the elimination step. ,NaOH H. 0 O

Write the equations that relate the rates of consumption of the reactants and the rates of formation of the products. 5Br+BrO 3 +6H + 3Br 2 +3H 2 O

An unknown compound with the molecular formula C3H,N2 has the CNMR and HNMR spectra shown below. 200 180 160 140 120 100 60 20 Multiple Hhaplet 19.6 10 8 (ppm) Propose a structure of this unknown compound based on this data.

Predict the product for each step of this reaction sequence. Na CHCH, H0 H Br

Calculate the pH of HCl and NaOH solutions after the addition of 0.75 L of water to (a) 100 mL of 2.5 M HCI 2

The H NMR spectrum of an unknown A with molecular formula CaH100 (in CDCI) is given below in Figure 1. The integrals and integral values for each signal are shown on the spectrum. 3.0 2.0 2.0 2.0 1.0 a 3.0 2.0 1.0 4.0 0.0 5.0 ,If the spectrum for unknown compound A is recorded in anhydrous CDCI then similar chemical shifts are obtained as shown in

Starting with a compound with 6 (or less carbons) propose a synthesis for the assigned compounds. Provide all reagents and show intermediates (3 points) CI. Br NO2

The following chemical reaction takes in aqueous solution: Write the net Ionic equation for this reaction.

ZnBr(aq) 2 KOH(aq) Zn(OH)(s)2 KBr(aq)

Our atmosphere provides us with some degree of shielding from cosmic radiation. Suppose shielding efficiency is approximately proportional to the shield material's density. What depth of water will provide the same shielding as the Earth's atmosphere? (Hint: the pressure at the surface of the Earth is 1 atm)

When protactinium-229 goes through two alpha decays, francium-221 is formed. Write the nuclear equation for this?

A 10 mL sample is added to a 300 mL BOD bottle. Dilution water is added to the sample bottle and the initial dissolved-oxygen concentration is measured as 8.5 mg/L. After the sample is sealed, the laboratory incorrectly takes a measurement of dissolved-oxygen reading on day 6 of 3 mg/L. If the BOD reaction rate coefficient for the sample is

Explain the following: a. Ethylene, C2I-14, is a planar molecule, but hydrazine, N2H4, is not. b. ICI, is linear, but NH, is bent. e. Of the compounds mercury(II) cyanate, Hg(OCN)2, and mercury(II) fulminate, Hg(CNO)2, one is highly explosive. and the other is not.