How much heat is required to convert 74 grams of ice at -4 C into 74 grams of water at 52 c

Description A large percentage of drugs (>60%) are based on natural products that have been isolated from nature. For this assignment, pick a drug that is a natural product or is based on the structure of a natural product. The compound is required to have at least 4 chiral carbons. Students must choose a unique compound. Post the structure of the drug. (1 point) List four functional groups that are in the molecule. (2 points) Identify the chiral carbons and configuration (R or S) for each carbon. (2 points) Describe what the drug is used to treat. (1 point) List the source of the natural product. (2 points) List an interesting fact or why you picked this compound. (1 point) Include reference(s). (1 point)

Aluminum is a reactive metal. It reacts with oxygen to form aluminum oxide as shown below.

4 Al(s) + 3 O (g) → 2 Al O (s)

I. When one mole of aluminum reacts with excess oxygen how many moles of aluminum oxide will be produced? II. When one mole of oxygen reacts with excess aluminum how many moles of aluminum oxide will be produced? III. When one mole of aluminum reacts with one mole of oxygen how many moles of aluminum oxide will be produced?

Use the Henderson-Hasselbach equation to calculate the pH of each solution:

I figured out part A by myself because the numbers were already in Molarity for me so I just plugged in numbers and calculated.

B. A solution that contains 0.785% C5H5N by mass and 0.985% C5H5NHCl by mass. (Here, I don't know what to do with the %'s to get the molarity in order to find the pH.)

C. A solution that contains 15.0 g of HF and 25.0 g of NaF in 125 mL of solution. (Here,i thought i could just use the g and mL to find molarity using mol/L but that led me to the wrong answers.)

Please explain your process clearly as possible because I would really like to be prepared when i see these kinds of questions on my exam. Thanks!

Sulfate (SO4^2-) concentration is 10 mg SO4^2-/L and monohydrogen sulfide (HS-) concentration is 2 mg HS-/L. What is the total inorganic sulfur concentration in mg S/L?

Why would the actual coefficients of a ferrous ammonium sulfate hexahydrate and the potassium iron oxalate complex in a balanced chemical equation describing the overall process not be required to compute the predicted weight of the product?

What is the difference between the Normal Hydrogen Electrode (NHE) and the Reversible Hydrogen Electrode (RHE)?

- Also, if a redox happens at the NHE of 0.2 V, please calculate the potential for the RHE at pH = 1.

1.In today experiment you will perform the aldol condensation between benzaldehyde (PhCHO) and acetone to synthesize dibenzalacetone. Answer the following questions regarding this reaction:

a.This reaction is an example of a mixed aldol condensation. Why is only one product formed and no mixture of compounds are obtained like in other aldol condensations? (Hint: Benzaldehyde cannot undergo “ALDOL” reaction by itself in presence of strong base (NaOH). Why?)

b.Look at the mmols of the reagents used in this reaction and specify the limiting reagent.

c.Explain why the NaOH is a catalyst in this reaction, rather than a reagent. (Hint - look at the reaction mechanism.)

d.Usually an aldol condensation must be heated in order to dehydrate the beta-hydroxy ketone to form the C=C. What is different about this product that causes it to dehydrate at room temperature?

e.Why does this product have a yellow color?

f.The IR spectrum of dibenzalacetone shows the C=O peak at lower wavenumbers (1639 cm^-1) than standard C=O frequency (1715 cm^-1)? Why do you think?

g. How would you change the procedures in this experiment if you wished to synthesize benzalacetone, C₆H₅CH=CHCOCH₃? Benzalacetophenone, C₆H₅CH=CHCOC₆H₅?

h.The name dibenzalacetone does not completely characterize the molecules made in this experiment. There are 3 isomeric dibenzalacetones, one melting at 100-110 °_max 330 nm,34,300; another melting at 60 °C, _max= 295 nm20,000; and a third, a liquid with_max= 287 nm Draw the structures of the three geometric isomers of dibenzalacetone (Z,Z; Z,E; E,E), and assign each one to the three molecules described in the previous paragraph.

i.Write the detailed mechanism for the formation of dibenzalacetone from benzalacetone and benzaldehyde.

Consider the titration of 30.0 mL of 0.0700 M (CH₃)₃N (a weak base; K_b = 6.40e-05) with 0.100 M HCl. Calculate the pH after the following volumes of titrant have been added:

(a) 0.0 mL pH = _________ (b) 5.3 mL pH = __________ (c) 10.5 mL pH = ____________
(d) 15.8 mL pH = _____________ (e) 21.0 mL pH =___________ (f) 39.9 mL pH = __________

The vapor pressure of liquid methanol, CH3OH, is 100 mm Hg at 294 K. A 5.59×10-2 g sample of liquid CH3OH is placed in a closed, evacuated 490 mL container at a temperature of 294 K. Calculate what the ideal gas pressure would be in the container if all of the liquid methanol evaporated in mm Hg Assuming that the temperature remains constant, will all of the liquid evaporate? What will the pressure in the container be when equilibrium is reached in mm Hg?

Predict whether aqueous solutions of the following compounds are acidic, basic, or neutral.

(a) Ba(C2H3O2)2	(b) NaNO3	(c) Na2SO4
(d) NaCl	(e) Fe(ClO4)3	(f) AlBr3

Calculate [OH ^-] and pH for each of the following solutions.



(a) 0.0034 M RbOH

[OH-] =_________ M

pH = _________

(b) 0.0872 g of KOH in 510.0 mL of solution

[OH -] =__________ M

pH = __________

(c) 79.8 mL of 0.00719 M Sr(OH)₂ diluted to 900 mL

[OH -] = __________ M

pH = ____________

(d) A solution formed by mixing 64.0 mL of 0.000880 M Sr(OH)₂ with 36.0 mL of 2.6 x 10^-3 M RbOH

[OH -] = ________M

pH =__________

What are the Ksp values for below 2.0×10−3 M AgNO3;RbCl 8.5×10−2 M CaI2;K2SO4

This is a Physical Chemistry Problem: For a particle in a cubic box of length a, how many states have energy in the range of 0 to 16(h²/8ma²)?

initial temperature = 24.3 degree celcuis

final temperature = 35.7 degree celcuis

50.0 ml of 0.740 M phospheric acid +50.0ml of 2.00M of sodium hydroxide

change in temperature = 11.4 degree celcius

calculate the following

1- what is the mass mixture in thecup ?

2-heat flowof the system in cup in KJ?

3- heat of system in cup (qrxn)in KJ?

4-initial moles of H3PO4 in the cup?

5- initial moles of NaOH in the cup?

6-delta H rxn in KJ(experimental)?

7-delta Hrxn in KJ (theoretical)

8- percent error?