How many grams of dipotassium oxalate (FM 166.22) should be added to 20.0 mL of 0.800 M HClO₄ to give a pH of 4.40 when the solution is diluted to 450. mL? (pK_a1 = 1.27 and pK_a2 = 4.266)
?g

Calculate the freezing point and boiling point of a solution containing 10.6 g of naphthalene (C10H8) in 114.0 mL of benzene. Benzene has a density of 0.877 g/cm3.

Calculate the freezing point of a solution. (Kf(benzene)=5.12∘C/m.)

Calculate the boiling point of a solution. (Kb(benzene)=2.53∘C/m.)

1. A block of an alloy of mass 27.0 g and at a temperature of 277.22 K is placed in a calorimeter containing 41.0 g of water at 357.74 K. If the final temperature of the alloy and water is 303.59 K, calculate the specific heat (in J/g/K) of the metal. The specific heat of water is 4.184 J/g/K. Express your answer to three significant figures in scientific notation.

2.A 0.439 g sample of solid N(CH₃)₄Cl (s) is dissolved in 494 mL of water in a coffee cup calorimeter. Once all of the N(CH₃)₄Cl (s) is dissolved in the water, the final temperature of the solution is found to be 13.59°C. If the initial temperature of the water in the calorimeter was 23.49 °C, calculate the calorimeter constant (in J/K) for the coffee cup calorimeter. Report your answer to three significant figures. The heat of solvation of N(CH₃)₄Cl (s) is 4.08 kJ/mol.

Write the molecular, total and net ionic equations.

Potassium hydroxide +chromium(III) nitrate

Sodium metal + a large excess of water

Potassium perchlorate + sulfuric acid

Barium hydroxide + hydrobromic acid

Phosphoric acid+ magnesium chloride

Hydrocyanic acid+sodium hydroxide

Sulfuric acid+ barium chloride

Silver nitrate+ammonium bromide

Sodium hydroxide+ Aluminum sulfate

Sodium carbonate+ hydroiodic acid

A chemist claims to have discovered a new gaseous element, effuvium (Ef), which reacts with atmospheric nitrogen to form effuvium nitride: 2 Ef(g) + 3 N2(g) 2 EfN3(g) In a container initially containing N2 at 1.00 bar and Ef at 0.75 bar, the total pressure at equilibrium, according to the chemists measurement, is 1.4. Compute Keq for this reaction. Entry field with incorrect answer 0.84 The number of significant digits is set to 2; the tolerance is +/-1 in the 2nd significant digit.

Calculate [H3O+] and [OH−] for each of the following solutions at 25 ∘C given the pH.

Part A.) pH= 8.65

Part B.)  pH= 11.40

Part C.)  pH= 2.94

in a lab experiment to test the change in temperature of NaCl and the change in temperature of water:

Specific heat of NaCl is 0.88
specific heat of DI water is 4.2

in the experiment, the change in temperature for the water was much greater than the change in temperature of the table salt as well as the change in energy.
(when using equation E = g C × change in T)

why did this occur?

1. PF5 has five single bonds to the central atom. SF4 has four single bonds to the central atom and the central atom possesses a lone pair of electrons. How can this observation be used to explain the different bond angles you measured.

Write the summary on the Analysis of Copper using Flame atomic absorption.

Describe sources of experimental error and how it can impact the data collected ?

discuss what is matrix interference that might occur In this experiment ?

Estimate, on the basis of CTST, the pre-exponential factor at 300K for the following types of gas reactions:

a. a bimolecular reaction between an atom and a diatomic molecule with the formation of a linear activated complex.

b. a biomolecular reaction between two diatomic molecules that form a linear activated complex with no free rotation.

Calculate how many mL of 0.100 HCl should be added to how many grams of sodium acetate dihydrate (NaOAc * 2H2O, FM 118.06) to prepare 250.0 mL of 0.100 M buffer, pH 5.00.

Calculate the pH of a 0.10 M solution of barium hydroxide, Ba(OH)2. Express your answer numerically using two decimal places.

Calculate the pH of a 0.10 M solution of NaOHNaOH. Express your answer numerically using two decimal places.

Calculate the pH of a 0.10 M solution of hydrazine, N2H4. Kb for hydrazine is 1.3×10−61.3×10−6. Express your answer numerically using two decimal places.

Calculate the pH of a 0.10 M solution of hypochlorous acid, HOCl. Ka of HOCl is 3.5×10−8. Express your answer numerically using two decimal places.

Calculate the pH of a 0.10 M solution of HCl. Express your answer numerically using two decimal places.