Questions
Caproic acid is composed of C, H, and O atoms. The combustion of a 0.225g sample...

Caproic acid is composed of C, H, and O atoms. The combustion of a 0.225g sample yields 0.512g of CO2 and 0.209g of H2O. What is the empirical formula for the compound?

In: Chemistry

Mass- 83g Volume before candle was burnt - 1000 mL Volume after candle was burnt -...

Mass- 83g
Volume before candle was burnt - 1000 mL
Volume after candle was burnt - 964.2 mL
Atmospheric pressure - 1.09 atm
Temperature - 296 Kelvins

1) Using the ideal gas law, calculate the number of moles of air originally present in the 250 mL flask
2) calculate the number of moles of air present in the flask after the candles burnt
3) calculate the number of moles of oxygen consumed based on the ideal gas law calculations

In: Chemistry

A 1.00 L flask is filled with 1.45 g of argon at 25 ∘C. A sample...

A 1.00 L flask is filled with 1.45 g of argon at 25 ∘C. A sample of ethane vapor is added to the same flask until the total pressure is 1.450 atm .

What is the partial pressure of ethane, Pethane, in the flask? Express your answer to three significant figures and include the appropriate units.

In: Chemistry

Determine the vapor pressure of a solution at 55°C that contains 34.2 g NaCl in 375...

Determine the vapor pressure of a solution at 55°C that contains 34.2 g NaCl in 375 mL of water. The vapor pressure of pure water at 55°C is 118.1 torr. The van't Hoff factor for NaCl is 1.9

In: Chemistry

interrelationship between global warming, acid rain, ozone layer depletion, and photochemical smog?   

interrelationship between global warming, acid rain, ozone layer depletion, and photochemical smog?

  

In: Chemistry

12.       What is responsible for capillary action, a property of liquids? a)         surface tension b)         cohesive...

12.       What is responsible for capillary action, a property of liquids?

a)         surface tension

b)         cohesive forces

c)         adhesive forces

d)         viscosity

e)         two of these

32. Which of the following correctly states the relationship between temperature and the solubility of a substance in water?

a) The solubility of a substance in water increases as the temperature rises, especially for gases. b) The solubility of a substance in water decreases as the temperature rises, especially for ionic solids. c) The solubility of a substance in water with temperature cannot be accurately predicted, especially for ionic solids. d) The solubility of a substance in water decreases as the temperature lowers, especially for gases. e) Both A and D are correct.

In: Chemistry

Find the pH during titration of 20.00ml of 0.1000 M triethylamine, (CH3CH2)3N (Kb=5.210^-4), with 0.1000M HCL...

Find the pH during titration of 20.00ml of 0.1000 M triethylamine, (CH3CH2)3N (Kb=5.210^-4), with 0.1000M HCL solution after the following additions of titrants a) 10.00mL b) 20.70 mL c) 27.00 mL

In: Chemistry

calculate the pH for a strong acid + strong base titration in which 5.00 mL of...

calculate the pH for a strong acid + strong base titration in which 5.00 mL of the M(OH)2 was transferred via pipet to a beaker and HCl was added from the buret.

Concentration of base is 0.0721 M

Concentration of acid is 0.0524 M

Please show work.

Calculate the pH:

a) before any HCl is added

b) after the addition of 4.00 mL HCl

c) after the addition of 9.00 mL HCl

d) 4.00 mL beyond the equivalence point

In: Chemistry

Problem 5: Find the differential and total cross sections in the first Born approximation for elastic...

Problem 5: Find the differential and total cross sections in the first Born approximation for elastic scattering of a particle of mass m, which is initially traveling along the z-axis, from a nonspherical, double-delta potential V (~ r) = V0δ(~ r − aˆ k)+V0δ(~ r+aˆ k), where ˆ k is the unit vector along the z-axis.

In: Chemistry

1.Calculate the number of moles of solute present in am aqueous solution of 86.3 g of...

1.Calculate the number of moles of solute present in am aqueous solution of 86.3 g of 0.160 m KCl.

2. The density of toluene (C7H8) is 0.867g/mL, and the density of thiophene (C4H4S) is 1.065 g/mL. A solution is made by dissolving 9.38g of thiophene in 270 mL of toluene. Calculate the (a) percentage and (b) Molality of thiophene.

In: Chemistry

A combustion analysis of a 0.44g sample of an unknown compound yields 0.88 g CO2 and...

A combustion analysis of a 0.44g sample of an unknown compound yields 0.88 g CO2 and 0.36 g H2O. If the sample a molar mass of 132 g/mol, what is the molecular formula of the sample?

In: Chemistry

7. You are given 2.263 g of a mixture of KClO3 and KCl. When heated, the...

7. You are given 2.263 g of a mixture of KClO3 and KCl. When heated, the KClO3 decomposes to KCl and O2, 2 KClO3 (s) → 2 KCl (s) + 3 O2 (g), and 632 mL of O2 is collected over water at 20 °C. The total pressure of the gases in the collection flask is 736 torr. What is the weight percentage of KClO3 in the sample? The formula weight of KClO3 is 122.55 g/mol. The vapor pressure of water at 20 °C is 17.5 torr.

In: Chemistry

Imagine that you are in chemistry lab and need to make 1.00 L of a solution...

Imagine that you are in chemistry lab and need to make 1.00 L of a solution with a pH of 2.50. You have in front of you

100 mL of 6.00×10−2 M HCl,

100 mL of 5.00×10−2 M NaOH,

and plenty of distilled water.

You start to add HCl to a beaker of water when someone asks you a question. When you return to your dilution, you accidentally grab the wrong cylinder and add some NaOH. Once you realize your error, you assess the situation. You have 82.0 mL of HCland 87.0 mL of NaOH left in their original containers.

Assuming the final solution will be diluted to 1.00 L , how much more HCl should you add to achieve the desired pH?

In: Chemistry

If acidic H2O2 is mixed with Fe^2+, which reaction occurs: the oxidation of Fe^2+ to Fe^3+...

If acidic H2O2 is mixed with Fe^2+, which reaction occurs: the oxidation of Fe^2+ to Fe^3+ or the reduction of Fe^2+ to Fe? Give the balanced redox reaction for each possibility and explain your reason for selecting the reaction which will occur. Assume standard solution concentrations.

For a) I have:

red: H2O2 + 2H+ + 2e- ---> 2 H2O E=+1.78 V

oxi Fe2+ ----> Fe3+ + e- E=-0.77V

Ecell = 1.01V

I'm stuck on b) but for the explanation I think I understand that the one which is more positive is more thermodynamically favoured, but if I'm wrong on this I'd appreciate a pointer in the right direction.

In: Chemistry

Suppose you were asked to carry out a crossed-aldol condensation reaction between 4-methylbenzaldehyde and 3,3-dimethylbutanal modelled...

Suppose you were asked to carry out a crossed-aldol condensation reaction between 4-methylbenzaldehyde and 3,3-dimethylbutanal modelled after an experiment performed with benzaldehyde and acetone, a. what product would you expect to make? Write the equation showing the detailed structures of reactants and products? b. propose a detailed mechanism for this reaction? c. what unwanted by-product might be expected in this experiment? Write the relevant equations with detailed structures? What experimental strategy might you attempt to minimize the formation of this by-product. d. how would your major product react with 2,4-dinitrophenylhydrazine? write an equation to depict the relevant details and describe what is observed visually. e. how would your major product react with molecular bromine in carbon tetrachloride? describe what is observed visually.

In: Chemistry