Chemgam

This page lists questions and answers that were posted by visitors named Chemgam.

Questions

The following questions were asked by visitors named Chemgam.

The rate constants for a first order decay reaction are found to be: K287.3C = 1 X 10-4s-1 K327.4C = 19.2 X 10-4s-1 (a) Determine the value, in s-1 of K250C (b) How long will it take, at 350C, for the reactant to decay to 1% of its original concentration?...

For AsClF4^2-: a)Name the hybridization of the orbitals of the central atom. i)s ii)sp iii)sp2 iv)sp3 v)sp4 vi)sp3d vii)sp3d2 b)Estimate the Cl-As-F bond angle. i)Slightly less than 90 ii)Exactly 90 iii)Slightly greater than 90 iv)Slightly less than 109.5...

(a) What is the pH of 50 mL of a 0.2M glycolic acid aqueous solution after adding 5 mL of 0.25 M KOH? The pKa of glycolic acis is 3.83 at 25 Celsius. (b) Classify each of the following compounds as either "acidic", "basic", or "amphoteric" (able to act as...

(a) Propylene, H2C=CH-CH3, can be reacted to form a polymer known as polypropylene (PP). What type of polymerization reaction is most appropriate for the formation of polypropylene? i)Addition Polymerization ii)Anionic Polymerization iii)Condensation Poly...

Shown below is a rough sketch of the unary phase diagram (pressure vs. temperature) for carbon dioxide , dry ice. Note the diagram is not drawn to scale and contains breaks in the axes to signify this. Using the diagram, answer the following questions: (a...

(a) What is the distance between second nearest neighbor atoms in vanadium? Express your answer in cm. (b) What is the interplanar spacing between (110) planes in vanadium? Express your answer in cm. (c) At what angle must (110) planes of vanadium be expo...

Identify the element that, acting as a target in an x-ray tube, generates Lα radiation of wavelength, λ, equal to 3.07 nm (3.07 x 10-9). i) Cu ii) Ni iii) Li iv) Ti v) K vi) Mo vii) W

(a) The solubility of bismuth iodide (BiI3) in water is 4.891 x 10-3 M. Calculate the value of the solubility product. The dissolution products are Bi^3+ (aq) and I^- (aq). (b) Do you expect the solubility of (BiI3) in 0.1 M NaCL (aq) to be equal to, grea...

(a) Silicon (50 g) has been doped with 27 mg of antimony (Sb). Determine the concentration of free charge carriers (carriers/cm3) at room temperature in this material. (b) Calculate the absorption edge of this material. Express your answer as a wavenumber...

The vacancy fraction of a particular metal is found to double as the temperature of the metal is increased from 700 degrees C to 850 degrees C. Calculate the enthalpy of vacancy formation for this metal. Express your answer in units of eV.

For each pair of compounds, identify the one with the higher boiling point. I)GeCl4 or SnCl4 II)PF3 or PF5 III)H2O or H2S

Arginine O 2.01 H2N---CH--C----OH 9.02 CH2 CH2 CH2 NH 12.48 C==NH NH2 ________________________________________ 9.78 O 2.35 H2N----CH---C----OH CH3 Glycine ________________________________________ Shown above are images of two amino acids, along with the p...

The energy versus bond length for the average bond in two solids, A and B, is shown below. Atoms in the two solids have the same number of nearest neighbots. (a) Which solid has the largest cohesive energy? A or B (b) Which solid has the smallest bond ene...

Consider the following surfactants: (a) Which are nonionic surfactants? i) A ii) B iii)C iv) D v) E

Answers

The following answers were posted by visitors named Chemgam.

a) 11.13 b) 10.76

Thank you for a) Any ideas for (b) Which are likely to have much lower critical micelle concentrations? A B C D E (c) Which surfactant is more likely to form non-spherical micelles? A B C D E The surface tension versus concentration for a surfactant in aq...

Jasmin, Thank you for the explanation.

a)4.27*10^-6 b)536.7

Thank you a)3.03*10^-8 b) 2.14*10^-8 c) 33.2

27*(4.891*10^-3)^4

Thank you. (a) B E (b) B E (c) E (d) critical micelle concentration (e). Region B (f). 0

any ideas on a)? b) A c) F d) D e) C, D, E f) E

Anonymous is right! a)5.11 atm and -56.3 b) I c) 73 atm and 31.1 d) 1 atm -78.5

Had the answer from someone else and still awaiting the formula to double check.

Same here. Received a red X on the answer.

Thank you for the explanation.

E = P^2/2Me + E(first ionization) P= h / BroglieWavelength E(first ionization)=21.7*10^-19 Me= 9.1*10^-31 h= 6.626*10^-34 frecuency(hz)= E / h

E = P^2/2Me + E(first ionization) P= h / BroglieWavelength E(first ionization)=21.7*10^-19 Me= 9.1*10^-31 h= 6.626*10^-34 frecuency(hz)= E / h