aishafakhar887

Determine the pH of a buffer solution that has a pyridine concentration of 0.20M, and the concentration of the pyridinium ion

is 0.40 M, knowing that the apparent dissociation constant of pyridine is 1.50 x 10-9.

Sodium borohydride (NaBH4) is used industrially in many
organic syntheses. One way to prepare it is by reacting sodium
hydride with gaseous diborane (B2H6). Assuming an 88.5% yield, how many grams of NaBH4 can be prepared by reacting 7.98 g of sodium hydride and 8.16 g of diborane?

Calculate the [H +], [OH-], pH and pOH of a 0.5 M HNO3 solution.

What is the Lewis structure for (CH2)3NH

In the absence of oxygen, glucose, C6H12O6(aq), can undergo fermentation producing ethanol, C2H5OH(l), and carbon dioxide, CO2(g), as represented by the following equation.
C6H12O6(aq) → 2C2H5OH(l) + 2CO2(g)
Assume the value of ∆f H° for C6H12O6(aq) is the same as the value of ∆f H° for C6H12O6(s).
 The enthalpy change associated with the fermentation reaction is?

How many grams of beryllium chloride are needed to make 125 mL of a 0.050 M

solution?

A 10.0 g sample of potassium bromide is treated with perchloric acid solution. The reaction mixture is cooled and solid KClO4 is removed by filtering, then it is dried and weighed.
KBr (aq) + HClO4 (aq) KClO4 (s) +HBr (aq) The product weighed 8.8 g. What was the percent yield?

An aqueous solution containing 55.19 g of an unknown sugar per 250,0 of solution has an osmotic pressure of 15.77 atm at 25.0 degrees * C . What is the molar mass of the unknown sugar?

An unknown element was tested using a spectroscopic technique. Light was emitted from the sample at a wavelength of 525.6 nm. Calculate the energy of a photon and the energy of one mole of photons of the light.

Chemical name of caocl2

An atom of oxygen has an atomic number of 8 and a mass number of 18. How many of each type of subatomic particles does it contain 

Z is a 0.1 M solution of malic acid, C4H605 in water

(Relative atomic mass: C 12; O 16; H 1).

(a) Show how you would prepare 1 dm3 of solution Z.

(b) Show the relationship between the number of moles of malic acid and its molar concentration.

Calculate mass percent of oxygen in zinc bromate

A solution contains 1.0 x 10-5 M Na3PO4. What is the minimum concentration of silver nitrate that would cause precipitation of solid silver phosphate (Ksp = 1.8 x 10-18)?

What volume of 0.0441M sulphuric acid is required to titrate 25cm^3 of 0.1M sodium hydrogen carbonate(round off to two decimal places)

. A 1.248 g limestone rock, which contains CaCO3 and other compounds, is pulverized and treated with 30.00 mL of 1.035 M HCl solution. The excess acid requires 11.56 mL of 1.010 M NaOH for neutralization. Calculate the percent by mass of calcium carbonate in the rock, assuming it is the only substance reacting with the HCl solution.

Consider 6.82 g Sr(NO3)2 is dissolved in enough water to form 0.500 L solution. A 0.100 L sample is withdrawn and titrated with a 0.0335 M solution of Na2CrO4. What volume of Na2CrO4 solution is needed to precipitate all the Sr2+(aq) as SrCrO4?

Mevacor is used clinically to lower serum cholesterol levels. (i) How many chiral centers and how many stereoisomers does Mevacor have?  

Why does an impure compound start melt at a lower temperature?

define spin-spin coupling of NMR using 1,1- dichloroethane

Which of the following pairs represent trihydric phenols?

Select one:

a. Resorcinol and quinol

b. Hydroxyquinol and quinol

c. Phloroglucinol and hydroxyquinol

d. Catechol and resorcinol

How will you prepare isopropanol and acetic acid from CH3MgBr?

The Concentration of HCl, a strong acid, is 0.5 mol/L. If 20 mL HCl is needed to titrate 40 mL of NaOH, what is the Concentration of NaOH?

2. What would be the molar concentration of a HCL solution if 25.0 mL of the solution is neutralized by 15.5 mL of 0.800 mol/L NaOH?

3. a) Explain what an equivalence point is in a titration.
b) What is the purpose of an indicator in the solution with the unknown concentration?

4. A strong acid and a weak acid that are both 1.0 mol/L react differently with zinc. Choose two acids and with the aid of equations and dissociation, explain why this is the case.

 A 400 mL buffer solution was prepared by reacting sodium acetate, CH3COONa,

with 1.00 M acetic acid, CH3COOH, with a pH of 4.56 Calculate the mass of

CH3COONa required to prepare the solution. Ka CH3COOH= 1.75 x 10-5

. 

Write the mechanism of the following reaction:
(2)
n -BuBr + aq.KOH
n-BuOH + KBr

What mass of lead(II) chloride forms in the reaction of 24.3 mL of 1.34
M lead(II) nitrate and 38.1 mL of 1.22 M sodium chloride?

Consider the reaction: 

3NO (g) ⇆ N2O (g) + NO2 (g) 

What is the expression for Kc for this reaction?

2. A 16.0 mL aliquot of a 0.220 M solution of H2SO4 is titrated with a 0.211 M NaOH solution. What volume (mL) of base will it take to reach the equivalence point?

 Calculate the molarity of an HCl solution if 26.4 mL of the solution neutralizes 30.0 mL of a 0.120 molar solution of Ba(OH)2.

A 35.0 mL sample of 1.00 M KBr and a 60.0 mL sample of 0.600 M KBr are mixed. The solution is then heated to evaporate water until the total volume is 50.0 mL. What is the molarity of the KBr in the final solution?
   

What is the powerhouse of the cell?

What bone in the body is the smallest?

polymerization of isobutylene using borontrifluoride as catalyst  and water as co-catalyst

) Describe how you would prepare a 50.0 mL solution of 4.00 M K2SO4. Calculate the volume of 4.00 M K2SO4 that is needed to prepare 600. mL of a 0.0200 M solution of K2SO4. Calculate the molar concentration of K+ ions in the 0.0200 M solution

 Draw the Kekule stucture of ch3cho 

Similarity of polyp and medusas of obelia

How many minutes are there in three and a half hours?

Write the net ionic equations for silver nitrate titrated with 0.1214M potassium thiocyanate requiring 14.42ml to reach end point 

• A mass of 3214 g of sodium bicarbonate was dissolved and diluted to 250.00 ml of aqueous solution. A 29.55OX mL of sodium bicarbonate solution was used to neutralise

25.00 ml of H2SO4 solution during a titration. Calculate the molar concentration of H2SO4 solution.