Balance these equations:

HCl+CaCO₃=

HCl+Na₂CO₃=

HCl+NaOH=

NaOH+FeCl₃=

CoCl₂+AgNO₃=

CuSO₄+Na₂CO₃=

CuSO₄+BaCl₂=

Na₃PO₄+CuSO₄=

Na₃PO₄+NiCl₂=

Na₃PO₄+BaCl₂=

NH₄Cl+AgNO₃=

Lactic acid is very good at penetrating the skin. Because of this, it is used in a number of products for skin care, such as exfoliating creams and chemical peels, and in formulations for transdermal delivery of medications, such as topical ointments and extended release patches for delivery through the skin. Lactic acid has a pKa of 3.86 in water at 25o C.

After graduation, you land your dream job at a small biotech firm specializing in novel antimicrobial agents. They have just developed a new drug, Poly-XSeption-L®, to help prevent antibiotic-resistant infections during local surgeries. Poly-XSeption-L® is to be applied to the skin at the site of the surgery in a liquid formulation containing lactic acid.

(a) The initial formulation being tested is a 1.0 wt% solution of Poly-XSeption-L® in a 0.015 M solution of aqueous lactic acid. Neglecting the effect of the antibiotic on the solution, what would you estimate the pH of this solution to be? State any assumptions you make.

(b) In clinical studies, it was found that the acidity of the initial formulation caused some problems with local irritation, and that Poly-XSeption-L® was not as effective below a pH of 4.2. It is proposed that sodium lactate be added to create a buffered solution with pH = 4.2. What concentration of sodium lactate should be used to achieve this pH?

The reaction

                                    NO(g) + O₃ -> NO₂(g) + O₂(g)

was studied in 2 experiments under pseudo-first order conditions.

a) [O₃] = 1x10¹⁴ molecules/cc in excess

the [NO] varied as follows   {Note, time is in msec (1 msec = 1x10^-3 s)!}

            time (msec)                 NO (molecules/cc)

                        0                      6x10⁸  

                        100                  5x10⁸  

                        500                  2.4x10⁸

                        700                  1.7x10⁸

                        1000                9.9x10⁷

b) [NO] = 2x10¹⁴ molecules/cc in excess     

            time (msec)                 O₃ (molecules/cc)

                        0                      1x10¹⁰

                        50                    8.4x10⁹           

                        100                  7x10⁹

                        200                  4.9x10⁹

                        300                  3.4x10⁹

a) what is the order of reaction with respect to NO?

b) what is the order of reaction with respect to O_3?

c) what is the overall rate law?

d) what is the pseudo-first order rate from experiment a); what overall rate coefficient does this give? (overall rate should be in cm³ molecule^-1 s^-1.)

e) what is the pseudo-first order rate from experiment b); what overall rate coefficient does this give?

Use Hess's law and the measured mean enthalpy changes for the NaOH-HCl(36.2) and NH3-HCl(31.9) reactions to calculate the enthalpy change to be expected from the reaction: NaOH + NH4Cl----NaCl + NH3 +H2O

What is the pH of 0.1 M FeSO4 please show all steps

A beaker with 1.30×102 mL of an acetic acid buffer with a pH of 5.000 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 5.00 mL of a 0.370 M HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.740.

A 100.0 ml sample of 1.00 M NaOH is mixed with 50.0 ml of 1.00 M H2SO4 in a large Styrofoam coffee cup; the cup is fitted with a lid through which passes a calibrated thermometer. the temperature of each solution before mixing is 22.9°C. After adding the NaOH solution to the coffee cup and stirring the mixed solutions with thermometer; that the specific heat of the mixed solutions is 4.18 J/(g•°C), and that no heat is lost to the surroundings.

a) Write a balanced chemical equation for the reaction that takes place in the Styrofoam cup.

b) Calculate the enthalpy change per mole of H2SO4 in the reaction.

What is the nuclear binding energy per nucleon of potassium-40? Particle Mass (amu) K-40 39.9632591 Neutron 1.008701 Proton 1.007316 Electron 0.000549 (1 kg = 6.022 × 1026 amu; NA = 6.022 × 1023 mol–1; c = 2.99792458 × 108 m/s) 1.33 × 10–12 J/nucleon 5.33 × 10–11 J/nucleon 5.64 × 10–11 J/nucleon 1.41 × 10–12 J/nucleon 2.97 × 10–12 J/nucleon

Define Z-effective for: He, Mercury, Xenon, Argon and Neon ? Please explain

Imagine that you have a 7.00 L gas tank and a 3.00 L gas tank. You need to fill one tank with oxygen and the other with acetylene to use in conjunction with your welding torch. If you fill the larger tank with oxygen to a pressure of 155 atm , to what pressure should you fill the acetylene tank to ensure that you run out of each gas at the same time? Assume ideal behavior for all gases.

The Ksp of PbBr2 is 6.60*10^-6 M^3. What is the molar solubility of PbBr2 in pure water?

What is the molar solubility of PbBr2 in 0.500 M KBr solution?

What is the molar solubility of PbBr2 in 0.500 M Pb(NO3)2 solution?

1. Calculate the pH during the titration of 25.00 mL of 0.1000 M LiOH(aq) with 0.1000 M HI(aq) after 24.2 mL of the acid have been added.

2. Calculate the pH during the titration of 30.00 mL of 0.1000 M CH₃CH₂COOH(aq) with 0.1000 M LiOH(aq) after 12 mL of the base have been added. K_a of propanoic acid = 1.3 x 10^-5.

Please help these questions!

For the following reactions please balance the equation and convert to a net ionic equation (see above) and give the correct physical state of each reactant and product in the net ionic equation ( s, l, g or aq), (net ionic equations may be reported in data and calculation section and need not be repeated here). (a) BaCl2 + Na3PO4 ---> Ba3(PO4)2 + NaCl (b) BaCl2 + Na2SO4 ---> BaSO4 + NaCl (c) BaCl2 + Na2CO3 ---> BaCO3 + NaCl (d) BaCl2 + Na2SO3 ---> BaSO3 + NaCl (e) BaSO3 + HNO3 ---> SO2 + H2O + Ba(NO3)2 (f) BaCO3 + HNO3 ---> CO2 + H2O + Ba(NO3)2 (g) Ba3(PO4)2 + HNO3 ---> H3PO4 + Ba(NO3)2 (h) AgNO3 + NaI ---> AgI + NaNO3 (i) AgNO3 + NaBr ---> AgBr + NaNO3 (j) AgNO3 + NaCl ---> AgCl + NaNO3 (k) NaI + Cl2 ---> I2 + NaCl (l) NaBr + Cl2 ---> Br2 + NaCl (m) 2NaNO3 + 2H2SO4 + 2FeSO4 ---> 2NO2 + Fe2(SO4)3 + 2H2O + Na2SO4 (n) 3NaNO2 + H2SO4 ---> 2NO + H2O + NaNO3 + Na2SO4 (o) 2NaNO2 + 2H2SO4 + 2FeSO4 ---> 2NO + Fe2(SO4)3 + 2H2O + Na2SO4 (p) H2SO4 + Na2CO3 ---> CO2 + Na2SO4 + H2O (q) H2SO4 + Na2SO3 ---> SO2 + Na2SO4 + H2O

Q1: If the theoretical yield of a reaction is 24.8 g and the actual yield is 18.5 g, what is percent yield?

Q2: When 11.5 gram of C are allowed to react with 114.5 g Cu2O, 87.4 g of Cu are obtained. Determine the limiting reactant, theoretical yield and percent yield.

Q3:This reaction of 185 g of Fe2O3 with 95.3 g of CO produces 87.4 g of Fe. Determine limiting reactant, theoretical yield, and percent yield.

1. Why is it important to know the difference between acids and bases, in terms of safety?

2. Ionic bonds, covalent bonds and hydrogen bonds all help to hold chemical entities together. Distinguish between these types of bonding and explain which type of bonding is responsible for matching the base pairs in DNA.