When an ion-selective electrode for X was immersed in 0.0760 M XCl, the measured potential was 0.0450 V. What is the concentration of X when the potential is 0.0600 V? Assume that the electrode follows the Nernst equation, the temperature is at 25°C, and that the activity coefficient of X is 1.

[X+] = ??M

An elastic (stretchable) balloon made of a material that is permeable to water but not to any solutes is filled with an aqueous solution containing 0.1 M glucose and 0.3 M NaCl. The balloon is then sealed and completely immersed in an second aqueous solution with NaCl as the only solute. The balloon does not expand or contract. What is the concentration of NaCl in the solution that the balloon was immersed in (the second solution)? Assume all salts undergo complete dissociation.

A 38.40 mg sample of an organic acid composed of just carbon, hydrogen, and oxygen was burned in pure oxygen to give 37.54 mg CO2 and 7.684 mg H2O in a combustion analysis. In a separate experiment, the molecular mass was determined to be 90. In a titration, 40.2 mg of the acid dissolved in 50 mL of water required 14.28 mL of 0.0625 M NaOH for complete neutralization. Use these data to draw a reasonable Lewis structure for the compound.

Determine the empirical formula of the compound using the combustion analysis data.

Calculate the exact masses and relative isotopic abundances of all the isotopomers of dichloromethane. Consider only the two most abundant isotopes of carbon and chlorine, and ignore deuterium and tritium (i.e., assume the natural abundance of 1H is 1.000000). Summarize your results by giving in a table the empirical formula for each isotopomer with superscripted atomic masses, the nominal m/z and the exact m/z values for each in a table .

To calculate natural abundance, make a product of the natural abundance of each element raised to the power of the number of times it occurs in the molecule. Then multiply it by the number of distinguishable ways that you can make this isotopomer, if the nuclei are labelled. For example, for two C nuclei labelled A and B, there is only one way to make 13C-13C (13CA13CB) but there are two ways to make 12C-13C (i.e., 13CA12CB and 12CA13CB). When you’re done correctly, all the abundances should add up to 100%, so you can use this to check for errors.

Hydroxylamine is a weak base that readily forms salts used as antioxidants in soaps. What is the pH of a 0.025M hydroxylamine solution that has a Kb of 9.1x109 ?

One method for preparing alcohols involves hydration of alkenes with aqueous acids (such as sulfuric acid and water). In light of this fact, it seems surprising that the phosphoric acid promotes the elimination of cyclohexanol to give cyclohexene plus water at high temperatures, the very components required to make cyclohexanol. Why was your experiment successful?

write a detailed arrow pushing mechanism for the light initiated monochlorination of ethane

Problem 1. Consider a crystal with HCP structure, having an ideal c/a ratio. Complete parts (a)-(c) below.

(a) (1.0 pt max) Demonstrate that the ideal c/a ratio equals 2 6/3.

(b)(0.5 pt max) Find the volume of one unit cell for a given a value.

(c) (0.5 pt max) Demonstrate that the atomic packing factor for this crystal structure is  2/6.

Hints: (a) The c/a ratio is considered ideal when the distance from some atom to its nearest neighbors within the same hexagonally-packed layer equals the distance to its nearest neighbors belonging to a different layer.

(b) The volume of a prism is the product of the area of its base face and the height. Use the c/a ratio found in part (a).

(c) Find the relationship between the lattice constant a and the atomic radius R to calculate the APF value. Use the unit cell volume found in part (b)

Apply Hume-Rothery Rules to Copper and Tin. Then, apply them to copper and silver.

Atomic Radius of Copper = 128 pm

Atomic Radius of Tin = 140 pm

Atomic Radius of Silver = 144 pm

Please explain the following, thank you.

Why does the amine lone pair bind the protic hydrogen of an alcohol more tightly THAN an alcohol lone pair binds the protic hydrogen of an amine?

A cylinder fitted with a piston has an initial volume of 0.1 m3 and contains nitrogen at 150 kPa, 25 0C. The piston is moved, compressing the nitrogen until the pressure is 1 MPa and the temperature is 150 0C. During this compression process heat is transferred from the nitrogen, and the work done on the nitrogen is 20 kJ. Determine the amount of this heat transfer.

14.00 g of anhydrous sodium acetate (82.03 g/mol) was dissolved in 100.00 g of water, the heat capacity of the reaction mixture was 4.045 J/g K. The change in temperature was increased by 6.40 °C.
1. is this an exothermic or a.m. endothermic reaction?
2. the heat transferred (qsys), was?
3. the number of moles of anhydrous sodium acetate dissolved is?
4. the (delta H) of dissolution for anhydrous sodium acetate is?

what's the relationship between polymer structures and relative physical properties?

What is the pH of a solution containing 1.093 mol L^-1 of a weak acid with pK_A = 3.36 and 1.406 mol L^-1 of another weak acid with pK_A = 8.42 ?

You have 5 attempts at this question.

Remember: if you want to express an answer in scientific notation, use the letter "E". For example "4.32 x 10⁴" should be entered as "4.32E4".