List 3 possible reasons why a person might not observe a reaction even when the activity series indicates that it should. Please explain carefully. Thank you for your help.

3. You have been given the task of purifying a 60 mL sample of toluene. In order to develop your plan of action, you ask about the impurities likely to be present in the sample. You are told that it contains small amounts of acetone (~10%). a Which technique would you choose for the purification process? Why? (1 point) b. Clearly describe the procedure you would use. (3 points) c. What simple chemical test, performed with the original sample and the purified product, will help you confirm that the acetone impurity has been removed during the purification process? (1 point)

How can one prevent oiling out?

A sample of O2 gas has a volume of 19.0 L at a pressure of 1.50 atm and a temperature of 23 °C. What volume, in liters, will the gas occupy at 3.50 atm and 271 °C? Assume ideal behavior

3.0ml of starch solution+ 3.0ml amylase added after 50 minute, what color is it after iodine, what the amount of starch, what color is it after adding Benedict's test, what amount of maltose and enzymes activity?

3.0ml of starch + 3.0ml amylase added, what color is it after iodine, what the amount of starch, what color is it after adding Benedict's test, what amount of maltose and enzymes activity?

3.0ml of starch + 4 drops of 2.0M HCl+ 3.0ml amylase, what color is it after iodine, what the amount of starch, what color is it after adding Benedict's test, what amount of maltose and enzymes activity?

incubate on ice 3.0ml of starch + 3.0ml amylase added, what color is it after iodine, what the amount of starch, what color is it after adding Benedict's test, what amount of maltose and enzymes activity?

I have finished a lab but in finding the percent deviation I keep coming up with different answers using the formula.

Measured values for 4 unknown liquids are

6.6c and 80.7c.

-22.9c and 76.7c,

-43.8c and 81.6c,

5.5c and 80.1c

The literature values are

7.0c and 81c,

-23c and 77c,

-45.5 and 77.3c,

6.0c and 80c

Are these answers correct? 5.71% .37% .434% .39% 3.74% 5.56% 8.33% .125% ???

How is the shape of a monoprotic acid titration curve determined by the pk of the acidic proton?

Define the terms binding energy, stellar nuclesynthesis and mass defect. Why do lighter elements favor fusion reactions and heavier elements favor fission reactions?

Question 1.

* What is the pH of 30 ml of a 0.35 M acetic acid solution?(pKa = 4.74)

*What is the pH if you titrate the above 0.35 M acetic acid solution with 15 mL of a 0.30 M NaOH solution? (in what region would this be in)

*How many mL of 0.30 M NaOH do you have to add to reach the equivalence point? What is the pH of this equivalence point?

*What is the pH of this solution after you add 60 mL of 0.30 M NaOH Solution?

For this assignment, write a paper about a baking soda of interest that is either manufactured or purified from natural sources. In the body of the paper, address the following questions:

• Who discovered the baking soda and when?
• If naturally occurring, where is it found?
• Who manufactures or purifies it?
• What are the common physical and chemical properties?
• What are the common uses?
• Is it harmful? Describe and explain its effects.

Which of the following statements is true concerning the decomposition of liquid water to form hydrogen gas and oxygen gas? 2H2O(l) → 2H2(g) + O2(g)

a. ΔH is greater than ΔU because the pressure is constant.

b. ΔH is less than ΔU because of the pressure–volume work done by the gaseous products.

c. ΔH is less than ΔU because the atmosphere does pressure–volume work on the gaseous products.

d. ΔH equals ΔU because both are state functions.

e. ΔH is greater than ΔU because of the pressure–volume work done by the gaseous products.

The Answer is E. But I need help in understand why that is and why all the other answers are wrong.

Chromium is obtained by heating chromium(III) oxide with carbon. Calculate the mass percent of chromium in the oxide, and then use this value to calculate the quantity of Cr₂O₃ required to produce 620. kg of chromium metal.

I am going to a lab next week on Acids, Bases, PH and Buffers, but i need some help, especially on Buffers.

Q.5 Which solution(s) showed the greatest and which solutions(s) showed little or no change change in pH? Why? regarding which ones, i do understand that i need to do the lab first.

I understand bufferss resist a change in PH when a small amount of strong acid OR strong base is added to it. This means that the PH of the buffers does not change significantly (by more than 1 PH unit) when a small amount of strong acid or base its added Can you please give me an example? i dont understand when say (by more than 1 unit)

In contrast, unbuffered solutions will show significant PH changes ( greater than 1 PH unit) when a small amounts of strong acid or base are added. Can you give an example? i dont understand where it say (greater than 1 PH unit) i will appreciate your help.