Suppose you titrated your standard acid (KHP) with the base to be standardized, but added several drops extra of the base (i.e. stopped the titration after the phenolphthalein indicator in the solution turned very pink).

If this calculated value was used to determine the molar mass of the unknown acid, what type of error would you have for the molar mass of the unknown acid? (i.e. would you overestimate or underestimate the molar mass value?) Support your answer by, for every step in the calculation, determining whether the calculated value would be greater or less than it should be.

how to put formulate the question :
Calculate the number of atoms present in 3.752g sample of Pb? 

a) Write the net ionic equations for any reaction that occurs when each of the following salts are dissolved in water (if no reaction occurs, write "NR"):

ammonium nitrate

potassium bromide

cesium formate

b) When does the cation of a salt react with water. Illustrate answer using KBr and NH₄Br:

c) When does the anion of salt react with water. Illustrate answer using KBr and KF:

You dissolve a compound with a molecular mass of 289.49 in a 10-mL volumetric flask. You remove a 1.00-mL aliquot, place it in a 25-mL volumetric flask and dilute it to the mark. The absorbance of this diluted solution at 341 nm was 0.444 in a 1.000-cm cuvet. The molar absorptivity for this compound at 341 nm is ε341 = 6117 M–1 cm–1.

(a) What is the concentration of the compound in the cuvet?

(b) What is the concentration of the compound in the 10-mL flask?

(c) How many milligrams of compound were used to make the 10-mL solution?

Predict whether N₂ is likely to have a relatively high or low boiling point.

Dalton's Law Of Partial Pressure show all calculations!!

a.) Earth's atmosphere consist of 78% N2 and 20% O2, and other gases. What is the partial pressure of N2 and O2 in torr, when atmospheric pressure is 1 atm?

b.) Ammonia is completely decomposed to nitrogen and hydrogen as in question 9b) At the end of the experiement the pressure of the gas mixture is 866 mmHg. Calculate the partial pressures of N2 and H2

11)

What are the coefficients in front of NO₃^-(aq) and Cu(s) when the following redox equation is balanced in an acidic solution:
___ NO₃^-(aq) + ___ Cu(s) → ___ NO(g) + ___ Cu²⁺(aq)?

Select one:

A. 3, 6

B. 2, 6

C. 2, 3

D. 3, 4

12)

The values of ΔH°_f for the three states of benzene are approximately -22 kcal/mol, -11 kcal/mol, and 20kcal/mol. Which is the value for solid benzene?

Select one:

A. -22 kcal/mol

B. 20 kcal/mol

C. -11 kcal/mol

D. cannot be determined without additional information

13)

Calculate the total quantity of heat required to convert 25.0 g of liquid CCl₄(l) from 35.0°C to gaseous CCl₄ 76.8°C (the normal boiling point for CCl₄)? The specific heat of CCl₄(l) is 0.857J/gC its heat of fusion is 3.27kj/mol and its heat of vaporization is 29.82kJ/mol.

Select one:

A. 1.43 kJ

B. 6.28 kJ

C. 5.74 kJ

D. 0.896 kJ

18)

When heated, mercury(II) oxide decomposes into elemental mercury and oxygen:
2 HgO(s) → 2 Hg(l) + O₂(g) ΔH° = 181.6 kJ ΔS° = 216.4 J/K
Estimate the temperature at which HgO should begin to decompose if the partial pressure of O₂(g) is constant at 1.00 atm.

Select one:

A. 840°C

B. -34.8°C

C. 34.8°C

D. 566°C

19)

When 50.0 mL of 0.400 M Ca(NO₃)₂ is added to 50.0 mL of 0.800 M NaF, CaF₂ precipitates, as shown in the net ionic equation below. The initial temperature of both solutions is 25.00°C. Assuming that the reaction goes to completion, and that the resulting solution has a mass of 100.00 g and a specific heat of calculate the final temperature of the solution.
Ca²⁺(aq) + 2 F^-(aq) → CaF₂(s) ΔH° = -11.5 kJ

Select one:

A. 24.45°C

B. 26.10°C

C. 26.65°C

D. 25.55°C

Physical chemistry

. The osmotic of an aqueous solution at 351 K is 94 kPa and a density of 1,152 g/mL. Calculate the freezing point (in C) of the solution. The Kf for water is 1.86oC/m.

How does pentobarbital, pancuronium bromide, and potassium chloride accomplish cessation of life?

Please include a source(s)!! It is a necessity! Thank you.

If a temperature scale were bassed on the freezing point (5.5 degrees Celsius) and boiling point (80.1 degrees Celsius) of benzene, and the temperature difference between these two points was divided into 50 units called degrees X, what would be the freezing and boiling points of water in degrees X?

In addition to the molecular orbital treatment of H2, the ground state can be treated by the so-called valence bond (Heitler-London) approach, where individual covalent bonds are combined to form an antisymmetric wave function with spins up and down. Look up this approach and compare the results with the simple MO treatment in terms of bond energy (kJ/mol) and bond distance (pm).

10Na + 2NaNo3 yields 6Na2O + N2

how many grams of sodium oxide will be made by combining 25.0 grams of sodium with 47.0 grams of sodium nitrate?

Balance the given redox reaction.

NaClO₃ + H₂O + I₂ --> HIO₃ + NaCl

?please show all steps

Devise a procedure for the separation and purification of the mixture containing 0.25g benzoic acid, 0.20g benzil, 0.05 p-dichlorobenzene.

Available reagents: 1M NaOH, 1M HCI, 1M NaHCO3, 6 M NaOH, 6 M HCI, saturated solution of NaCl, diethyl ether, 95% ethanol, methanol, isopropyl alcohol, acetone, hexane, toluene, ethyl acetate, anhydrous sodium sulfate.

The Ka of acetic acid is 1.8 x 10^-5 at 25C.

a) What is the pH of a 0.5 M solution of acetic acid at 25C?

b)What is the pH of a solution made up of 20 mL of 0.5 M solution of acetic acid and 10 mL of 0.5 M sodium acetate?

c) If 10 mL of 0.1 M NaOH is added to the solution in part b, what is the final pH?

d) What is the pH of a solution containing equal concentrations of acetic acid and sodium acetate?