Get college assignment help at uniessay writers How many moles of ions are in 1.80 mol of K2SO4
Determine the final temperature of a gold nugget (mass=376g) that starts at 398k and loses 4.85 kJ to a snowbank when it is lost. The specific heat capacity of gold is 0.128 J/g C.
A student is preparing to perform a series of calorimetry experiments. She pours a 50.0mL sample of water at 345k into the calorimeter containing a 50.0mL sample of water at 298K. She records the final temperature of the water as 317K. What is the value of Ccal (calorimeter constant) for the calorimeter.
A chemical bond for which one of the bonded atoms provides both electrons for the bond is referred to as a: a. formal covalent bond b. coordinate covalent bond c. free radical bond d. double covalent bond e. VSEPR bond
Draw the lewis dot structure of CH3CH2CH2OH
Calculate the pH of a solution formed by mixing 150.0 mL of 0.10 M HC7H5O2 with 100.0 mL of 0.30 M NaC7H5O2. The Ka for HC7H5O2 is 6.5 × 10-5.
A person ate 0.186 pound of cheese (an energy intake of 1490 kJ). Suppose that none of the energy was stored in his body. What mass (in grams) of water would he need to perspire in order to maintain his original temperature? (It takes 44.0 kJ to vaporize 1 mole of water.)
If the interactions between two species is proportional to 1/(r^3), which of the following is likely involved? 1. chloromethane molecules in the solid phase 2. chloromethane molecules in the liquid phase 3. bromine molecules in the liquid phase 4. Na and H2O 5. ions in an ionic solid
The crossed aldol condensation of acetaldehyde with benzaldehyde is aided by the fact that benzaldehyde bears no alpha-proton. However, a possible competitive reaction is the “self-condensation” of two molecules of acetaldehyde. Slow addition of the acetaldehyde to a benzaldehyde solution containing an NaOH/ethanol/water mixture will often result in less self-condensation. Explain.
For 2CO(g) O2 2CO2(g);H = -560kj 2 mole CO(g) and 1 mole O2 are taken in 1 L vessel. Pressure inside the vessel changes from 70 to 40 atm. U at 500 K will be (1 atm L = 100 J)
Get college assignment help at uniessay writers How many Covalent Bonds are there in C4H7Br
How would you prepare 70.0 mL of 0.200 M HNO3 from a stock solution of 4.00 M HNO3
see attached wksht for help: Q1. Your class mate obtained the melting point of the solid obtained from vial C. He found it out to be113 °C – 135 °C. a. Is this what you would expect for a pure compound? Since this is not what you’d expect for a pure compound, what impurity is likely to be present? b. Explain how this impurity formed using a chemical equation. (1 Point) c. Is it possible to determine the percentage of the impurity formed? If yes, what was the mole percent of the impurity formed? (There are two possible answers—remember melting point?) (1 Point) d. What changes will you make to the experimental method so that this impurity does not form? Explain in detail. (1 Point) Q2. Organic compounds containing basic functional groups, such as amines, —NR2, can be converted into their water-soluble hydrochloride salts by treating them with dilute hydrochloric acid. Several drugs containing the basic amine functionality are formulated as their hydrochlorides, not just to improve their pharmacokinetic properties, but also to make them water-soluble. An example of a drug with an amine functional group is diphenhydramine (Benadryl), used for relief of certain allergy symptoms. Its amino group is protonated by dilute HCl; the structure of the hydrochloride salt is as follows: The pKa of diphenhydramine hydrochloride is 9.12. a. If a small amount of diphenhydramine hydrochloride is dissolved in excess aqueous 5% NaHCO3, what is the molar ratio of diphenhydramine and its conjugate acid? (1 Point) b. At what pH would the ratio of diphenhydramine to its conjugate acid be 1000? Show your work. (1.5 Points) c. Ten-stubs Needleman, a compounding pharmacist of dubious reputation, meant to mix diphenhydramine hydrochloride with aspirin, but he accidentally mixed it with phenacetin instead. To make matters worse, he put the mixture next to his morning coffee and accidentally added a teaspoon of sugar to the mixture. He has asked you to help him recover pure diphenhydramine from the mixture. Provide a flow chart for the isolation of diphenhydramine. Diphenhydramine is soluble in dichloromethane and hot water, and it is sparingly soluble in cold water, from which it can be recrystallized. Diphenhydramine hydrochloride is very soluble in cold water. The chemicals available are dilute NaOH solution, 5% NaHCO3 solution, 5% HCl solution, and dichloromethane. The equipment available includes all of the equipment available in this exercise. (4 Points)
in wet preservation of boiler why hydrazine conc. is kept 200ppm. any other chemicals can be used in wet preservation. is there any possibility of flow accelarated corrosion due to hydrazine
Calcium hydroxide and sulfuric acid can react to produce calcium bisulfate and water. When 0.0720 mol of sulfuric acid are reacted with 0.0240 mol of calcium hydroxide, how much calcium bisulfate, Ca(HSO4)2, will be produced?
Determine the wavelength (in nanometers) of an oxygen molecule at room temperature traveling at 475 m/s (You will have to find the mass of one oxygen molecule in units of kilograms).
how many hydrogen atoms are in 0.85 mole of allyl sulfide
Heat of formation of KHT
The decomposition of N2O5 in nitric acid is a first order reaction. It takes 4.26 min at 55 °C to decrease 2.56 mg of N2O5 to 2.50 mg. Find the rate constant k.
Why should the standarized NaOH solution be kept in a stoppered bottle? Why should you use a rubber stopper for this?
A piece of aluminum when placed in in a graduated cylinder of water causes the water to rise from 10.4 mL to 12.2 mL. The density of aluminum is 2.70 g/cm3. What is the mass of the peice of aluminum?
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