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3) What mass, in grams, of hydrogen gas, H₂(𝑔) can be produced from 144 milliliters of a 12.0 M hydrochloric acid solution, HC𝑙(𝑎𝑞), with excess zinc?

How many grams of Al2O3 is extracted from 250. g of FeO?  please explain.

The specific rotation of optically pure adrenaline in water at 25° is –53. A Chemist devised a synthetic route to prepare optically pure adrenaline but it was suspected that the product was contaminated with a small amount of the undesirable enantiomer. The observed specific rotation was found to be–45.calculate the % ee of the product 

A compound with molecular formula C4H8O has the following characteristics:
-Does not act with metallic Na
-with H2 acts in the presence of catalyst and gives composition B, (C4H10O)
-composition B reacts with excess HI hydrochloric acid to give two moles of the same alkane C halogen.
a) Find structured A, B, C and name them
b) Write the corresponding reactions.

Draw the structure of all stereoisomers belonging to the structure given the closed formula in the form of C4H10BrCl and make their names according to IUPAC rules.

How many atoms are present in 123g of Magnesium Cyanide

Define enthalpy of solvation

Draw the major organic product of the reaction shown.

Which of the following can be characterized as a strong base?

Determine the isoprene units in myrcene, alpha-pinene, farnesol, beta-carotene and vitamin A.

You are separating anthracene from benzoic acid via an extraction between ethyl acetate and a basic aqueous solution in a separatory funnel. How would you recover the anthracene?

Why is Zn(OH)₂ more soluble in HCl than in water?

The organic layer can also be extracted with NaOH_(aq) instead of using potassium carbonate (K₂CO₃). However, sometimes, initially two layers form in the separatory funnel when the base is first added to the organic layer. But during extraction, the solution has been reported to become warm. When the separatory funnel is put back into the ring stand to let separation occur, no separation is observed not even after standing for 5 minutes. What happened? Explain using a chemical reaction.

Aspirin is an acidic compound. Many aspirin products contain antacids in addition to the drug itself. Why might this be a useful addition to the medication?

Look at the densities of the elements on the periodic chart given in the introduction to 
measurements section of this lab manual. What general trend, an increase or decrease in 
density, do you see as you look from the top to bottom in a given group, vertical column 
of elements, for example Li to Fr?

Give two possible roles for piperidine.

A certain isotope X contains 23 protons and 28 neutrons. What is the mass number of this isotope? Identify the element.

Indicate how the concentration of each species in the chemical equation will change to reestablish equilibrium after changing the concentration of the reactant or product. An up arrow indicates an increase in concentration, a down arrow indicates a decrease in concentration, and leaving it blank means there is no change in the concentration.

Write an equation for the reaction of n-butyl alcohol with acetyl chloride. What gas evolved?

The cyclohexane derivative shown exists primarily in the more stable of the two available chair conformations. Give the position, axial or equatorial, of each of the three groups shown in the more stable chair conformation. If a group divides its time equally between axial and equatorial positions, indicate this with ax/eq.

To calculate the molar mass of the CO₂ gas created, we need to know its mass. Assume on Alka-Seltzer tablet has 50% by mass of each reactant. Use the mass of the tablet from your lab data, and, along with stoichiometric ratios and limiting reactant calculations from our moles unit, calculate the mass of CO₂ gas that should have been created in the lab activity.

Phenolphthalein, a common nonprescription laxative, is also an acid–base indicator that is colorless in acid and red in base. Phenolphthalein is synthesized by the acid-catalyzed reaction of phthalic anhydride with 2 equivalents of phenol.

(a) Propose a mechanism for the synthesis of phenolphthalein.

(b) Propose a mechanism for the conversion of phenolphthalein to its red dianion in base.

(c) Use resonance structures to show that the two phenolic oxygen atoms are equivalent (each with half a negative charge) in the red phenolphthalein dianion.

We make an approximately 0.04 M solution of KMnO₄ . We dissolve 500 mg of primary standard of sodium oxalate in 250 ml of water and use this to standardize. A volume of 39.07 ml is required to titrate the standard solution. What is the actual concentration of MnO₄^- ?

How would the geometry of the product (isoborneol) change (OH in an endo or exo position?) if all the methyl groups of camphor were replaced with H?

why is an electrothermal atomizer more sensitive than a flame atomizer

What is the chemical formula for Li+ and PO4-3

A 1.24M solution of sodium propionate (NaCH₃CH₂COO) with a density of 1.15 g/mL has an osmotic pressure of 48.5 atm at 16^oC.  Determine the van’t Hoff factor and the freezing point of the solution. Explain why the van’t Hoff factor is smaller than for an ideal solution

1. Why is it necessary to record the temperature in the experiment?.

2. Suppose the initial concentration of Fe³⁺ is increased from 0.001 M to 0.002 M. What effect would this have on the value of Kc?

3. 1.25 moles of NOCl were placed in a 2.50 L reaction chamber at 427ºC. After equilibrium was reached, 1.10 moles of NOCl remained. Calculate the equilibrium constant, Kc, for the reaction 2NOCl(g) 2NO(g) + Cl₂(g)

You find a bottle of MCO₃ (M is some metal) on the shelf in a chemistry lab, and you want to dissolve this in solution, so you try two methods. Note: the solubility of this compound in water is 3.9 x 10^-4 M. Remember to check any assumptions you make in your calculations or your setup.

a) Method 1: Dissolving MCO₃ in a solution of 1.00 molar M(NO₃)₂. Calculate the solubility in this M(NO₃)₂ solution and compare it to the solubility in pure water (i.e. state whether S is greater than, equal to, or less than S in pure water).

b) Method 2: Dissolving MCO₃ in an aqueous solution of pH = 4. Does this affect the solubility of MCO₃? Briefly answer qualitatively. Note: For H₂CO₃, K_a1 = 4.5 x 10^-7 and K_a2 = 4.7 x 10^-11

A solid laboratory sample contains two substances, lead(II) carbonate (PbCO₃) and barium carbonate (BaCO₃). A 5.000 g sample of this unknown was treated with aqueous nitric acid (HNO₃) to dissolve it, then, after further treatment to adjust the acidity, it was treated with an excess of potassium chromate solution (K₂CrO₄). The precipitate which formed, when dried carefully and weighed, has a mass of 6.276 grams. Calculate the percent, by weight, of lead(II) carbonate (PbCO₃) in this laboratory sample.

Use the following NMR and mass spectral data to identify the structures of an unknown compound. 1H NMR: δ = 0.92 (t, J = 6 Hz, 3 H), 1.32 (broad s, 12 H), 2.28 (broad s, 2 H), and 2.69 (t, J = 7 Hz, 2 H) ppm. Mass spectrum m/z (relative intensity) = 129 (0.6) and 30 (100).

1. 1.The experimental rate law of a simple reaction A → B + C is v = k[A]. (a) Determine total order of the reaction. (b) Imagine initial conditions at which the rate equals v0. Calculate the change in the reaction rate that will be observed when the concentration of A will be tripled.

2.Calculate the activation energy for a first-order reaction if its rate constant increases from 10 s–1 to 100 s–1 as the temperature increases from 300 to 330 K.

3.Consider a simple first-order reaction A → B. If you start with solution of 0.1 mol/L A, it takes 20 s to go to a concentration of 0.05 mol/L of A. (a) What is the value of the rate constant for this reaction? (b) Calculate half-life of the reaction.

In the following reaction, a Wittig reagent is generated in situ by mixing the phosphonium salt with a strong base, in the presence of an aldehyde (note that ester groups are generally not reactive toward Wittig reagents). Predict the product of this reaction. Note that NaHMDS is a strong base with a negative charge on nitrogen, like NaNH₂.

Mannose is an epimer of both glucose and talose but talose and glucose are not epimers. Please explain. (Hint : A mnemonic for the aldohexoses is "All Altruists Gladly Make Gum in Gallon Tanks": allose, altrose, glucose, mannose, gulose, idose, galactose, talose). Then draw in this order, the Fischer projections of the D-aldohexoses.