Two structures of alanine can be drawn that have a net charge of zero, but the predominant form of alanine at its pI is zwitterionic. Why is alanine predominantly zwitterionic rather than completely uncharged at its pI? What percent (to one significant figure) of alanine molecules would be in the completely uncharged form at the pI? Hint: pK1 of alanine is 2.35 and pK2 is 9.87.

Co(II) was used as an internal standard to analyze a sample of Ti(IV) with atomic absorption spectroscopy (AAS). A standard mixture containing 2.50 μg Co/mL and 2.47 μg Ti/mL measured by AAS produced a signal-to-signal ratio of 2.60 Ti: 1.00 Co. A mixture was prepared by combining 5.00 mL of a Ti(IV) solution of unknown concentration with 4.00 mL of a 12.4 μg/mL solution of Co(II). The absorbance of the mixture at the Ti(IV) wavelength was 0.119 and the absorbance at the Co(II) wavelength was 0.225. Determine the concentration, in moles per liter, of Ti(IV) in the original unknown solution.

which of the following statements are true?

a) the same nuclear changes (creation/destruction of specific nucleons) occur in beta decay as in alpha decay

b) half-lives for alpha-decaying radionuclides are about the same as half-lives for beta-decaying ones

c) alpha decay reactions and beta decay reactions follow kinetics of the same order

Dolomite, [CaMg(CO₃)₂] is found in a soil sample. A geochemist titrates 24.65 g of soil with 57.85 mL of 0.3315M HCl. What is the mass % of dolomite in the soil? ( Write answer to two decimal places, ex. 15.77)

Following is the acid/base reaction which occurs during the titration: CO₃^-2_(aq) + HCl_(aq) --> HCO₃^-_(aq) + Cl^-_(aq)

Consider a saturated solution of the salt MX3, which M is a metal cation with a 3+ charge and X is an anion with a 1− charge, in water at 298 K. Which of the following will affect the Ksp of MX3 in water?a. diluting the solution. b. raising the temperature of the solution. c. more than one of the above factors. d. addition of more M3+ to the solution e. the addition of more X- to the solution.

Calculate the pH of the solution at each step after the addition of i) 0.00mL ii) 2.30 mL, iii) 10.0 and iv) 16.0 mL of 0.50 M HCL to 100.0 mL of 0.10 M NH₃ solution.

The ΔG°\' of the reaction is -7.050 kJ ·mol–1. Calculate the equilibrium constant for the reaction. (Assume a temperature of 25° C.What is ΔG at body temperature (37.0° C) if the concentration of A is 1.8 M and the concentration of B is 0.75 M?

Identify the following species as electrolytes or nonelectrolytes:

CH₃OH

NH₄Cl

Ca(OH)₂

C₆H₆

RbClO₄

A titration involves adding a reactant of known quantity to a solution of an another reactant while monitoring the equilibrium concentrations. This allows one to determine the concentration of the second reactant. The equation for the reaction of a generic weak acid HA with a strong base is

HA(aq)+OH?(aq)?A?(aq)+H3O+(aq)

A certain weak acid, HA, with a Ka value of 5.61�10?6, is titrated with NaOH.

Part A:

A solution is made by titrating 9.00mmol (millimoles) of HA and 3.00mmol of the strong base. What is the resulting pH?

Part B:

More strong base is added until the equivalence point is reached. What is the pH of this solution at the equivalence point if the total volume is 45.0mL ?

How can you determine which compound is a stronger acid/base if neither compound is a strong acid or a strong base? Chapter 16, question 45 c. in chemistry a molecular approach textbook

Out of the choices provided, which is the best recrystallizing solvent for resorcinol and why?

a. Water

b. Petroleum ether

c. Ethanol

The equilibrium constant (Kp) for the following reaction is 4.40 at 2000.K.

H_2(g) + CO_2(g) <=> H₂O_(g) + CO_(g)

a) Calculate Delta G^o for the reaction. ____________ KJ/mol

b) Calculate Delta G for the reaction when the partial pressures are P_H2 = 0.28 atm, P_CO2 = 0.81 atm, P_H2O = 0.63 atm, and P_CO = 1.17 atm. ______________ KJ/mol

An equilibrium mixture contains 0.20 moles of hydrogen gas, 0.80 moles of carbon dioxide, 0.10 moles of carbon monoxide, and 0.40 moles of water vapor in a 1.00-liter container. How many moles of carbon dioxide would have to be added at constant temperature and volume to increase the amount of carbon monoxide to 0.20 moles? The equation for the reaction is:

CO_(g)+H₂O_(g) <=> CO_{2 (g)}+H_{2 (g)}

Determine the EMF of this equation 2Fe + 6HCl ----> 2FeCl3 + 3H2

and what is that Reduction and Oxidation.