A student collected the following data while using the procedure described in this module: 27.13 mL of 1.00 x 10^-2M EDTA soltuion was required to reach the ErioT end point for titration of 25.00 mL of the sample water. After boiling and filtering 100.00 mL of the water, the student diluted the filtrate to 100.0 mL with distilled water. To titrate 25.00 mL of the diluted filtrate, 26.40 mL of 2.00 x 10^-1 M EDTA solution was required. The studetn precipitated the Ca^2 ion as CaC2O4 from 75.00 mL of the water sample and removed the precipitate by filtration. The student then adjusted the water sample volume to 100.0 mL. To titrate 25.00 mL of the diluted filtrate, 7.43 of 1.00 x 10^-2 M EDTA solution was required Calculate the permanent water hardness in terms of total mmol of Ca^2 and Mg^2 ions.

Sketch a titration curve for 50 mL of 0.10 M HCl titrated with 0.15 M NaOH.

Include on the graph:

a) The initial pH

b) The volume of the equivalence point

c) The pH at the equivalence point

d) The pH after addition of 50 mL of NaOH

SHOW STEPS

386 km/s = _______ cm/s ?

386 km/s = ________ m/ms ?

1270 g/L = _______ g/mL ?

1270 g/L = ________ kg/mL ?

615 mK/s = _______ K/s ?

615 mK/s = ________ μK/ms?

2.999 mg/mL = _______ g/L ?

2.999 mg/mL = ________ μg/mL?

1) The reversible chemical reaction

A(aq)+B(aq)⇌C(aq)+D(aq)

has the following equilibrium constant:

K=[C][D][A][B]=5.2

a) Initially, only A and B are present, each at 2.00 mol L−1. What is the final concentration of A once equilibrium is reached?

b) What is the final concentration of D at equilibrium if the initial concentrations are [A] = 1.00 mol L−1 and [B] = 2.00 mol L−1 ?

In anaerobic cells glucose C6H12O6 is converted to lactic acid: C6H12O6 → 2CH3CH(OH)COOH. The standard enthalpies of formation of glucose and lactic acid are –1274.45 and –694.04 kJ/mol, respectively. The molar heat capacities (at constant pressure) for glucose and lactic acid are 218.86 and 127.6 J/mol K, respectively.

(4.a) Calculate the molar enthalpy associated with associated with the formation lactic acid from glucose at 298 K.

(4.b) What would the quantity in part (4.a) be if the reaction proceeded at a physiological temperature of 310 K?

(4.c) Based on your answers in parts (4.a) and (4.b) how sensitive is the enthalpy of this reaction to moderate temperature changes?

A cell membrane at 37°C is found to be permeable to Ca2+ but not to anions, and analysis shows the inside concentration to be 0.100 M and the outside concentration to be 0.001 M in Ca2+.

a) What potential difference in volts would have to exist across the membrane for Ca2+ to be in equilibrium at the stated concentrations? Assume that activity coefficients are equal to 1. Give the sign of the potential inside with respect to the outside.

b) If the measured inside potential is +100 mV with respect to the outside, what is the minimum (reversible) work required to transfer 1 mol of Ca2+ from outside to inside under these conditions?

chemical engineering
*An adult human being at rest produces roughly 0.40 mJ/h of thermal energy through metabolic activity. Use that fact to solve the following problems.
(a)
A college student who weighs 128 pounds put off a major assignment until the day before it was due and worked for eight hours to complete it. If she is modeled as a closed adiabatic system at constant pressure, her heat capacity and molecular weight are approximately the same as that of liquid water, and her temperature was normal when she began to work, what would her temperature have been by the time the assignment was finished?
(b)
Now model the student as an open system and assume that evaporation of perspiration (evaporative cooling) is the only mechanism for heat loss. How much weight would she have lost through evaporation if she maintained a constant body temperature?
(c)
Are either of the models in Parts a and b reasonable? Explain. What is the most likely explanation of what happened to the metabolic energy produced in her body?

What are the most important kind of intermolecular forces present in the following substances?

i) toluene, C7H8 (l)

ii) mercury , Hg (l)

iii) ammonia, NH3 (l)

b) Of the substances F2, Kr, CH4, and HF, which has

i) the smallest dipole-dipole forces

ii) the largest hydrogen bonding

iii) the largest dispersion forces

How would set up a serial dilution to cover a concentration range from approximately 21 µM to 120 µM of DHF in anassay (in the well) having a total volume of 200 µL of which 30 µL is DHF solution? You are provided a 800 µM DHFstock solution. You need to make a set of DHF dilutions in Eppendorf tubes first.   From these you will take 30 µL eachand dilute into total volume of 200 µL in the wells

can you plase give me the ansewer step by step please

Calculate the pH for each of the following cases in the titration of 50.0 mL of 0.200 M HClO(aq) with 0.200 M KOH(aq). The ionization constant for HClO can be found asfunction _parent.followURL,http://sites.google.com/site/chempendix/ionization

(a) before addition of any KOH

(b) after addition of 25.0 mL of KOH

(c) after addition of 30.0 mL of KOH

(d) after addition of 50.0 mL of KOH

(e) after addition of 60.0 mL of KOH

Explain why first electron affinities for neutral atoms tend to increase going across a period (i.e., from left to right) and up a group (i.e., bottom to top) in the Periodic Table.

what is the mechanism to get ornithine from glutamate-5-semialdehyde

How do metal salts affect catalase activity? Why are some metal salts considered to be activators and others are considered to be inhibitors? How do you know if a metal salt is an activator or inhibitor? For example, between K, Mg, Zn, Ca, and Fe, which metal salt would be the activator and which would be the inhibitor? How do you know?

Consider the following system at equilibrium where Delta H° = 108 kJ, and K_c = 1.29×10^-2, at 600 K.

COCl₂(g) <---> CO(g) +  Cl₂(g)  

If the VOLUME of the equilibrium system is suddenly  increased at constant temperature:

A) Calculate the mass defect of the oxygen nucleus 16  8O. The mass of neutral 16  8O is equal to 15.994914 atomic mass units. Answer in amu.

B) Calculate the binding energy E of the oxygen nucleus 16  8O (1eV=1.602×10−19J). Answer in MeV

C) Calculate the binding energy per nucleon of the oxygen nucleus 16  8O. Answer in MeV / nucleon