Questions
How can one prevent oiling out?

How can one prevent oiling out?

In: Chemistry

A sample of O2 gas has a volume of 19.0 L at a pressure of 1.50...

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

In: Chemistry

3.0ml of starch solution+ 3.0ml amylase added after 50 minute, what color is it after iodine,...

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?

In: Chemistry

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

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% ???

In: Chemistry

If bacteria are constantly evolving and developing resistance to things like antibiotics, why don't they become...

If bacteria are constantly evolving and developing resistance to things like antibiotics, why don't they become resistant to soap, ethanol or bleach?

In: Chemistry

find the pH in a mixture of: a) 50 ml 0,10 mol/L HCL and 10 mL...

find the pH in a mixture of:
a) 50 ml 0,10 mol/L HCL and 10 mL 0,50 mol/L NaOH

b) 50 mL 0,10 mol/L HCL and 20 ml 0,50 mol/L NaOH

c) 100 mL 0,20 mol/L CH3COoH and 50 mL 0,20 mol/L NaOH

thx

In: Chemistry

How is the shape of a monoprotic acid titration curve determined by the pk of the...

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

In: Chemistry

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

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

In: Chemistry

Question 1. * What is the pH of 30 ml of a 0.35 M acetic acid...

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?

In: Chemistry

For this assignment, write a paper about a baking soda of interest that is either manufactured...

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.

In: Chemistry

Which of the following statements is true concerning the decomposition of liquid water to form hydrogen...

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.

In: Chemistry

Chromium is obtained by heating chromium(III) oxide with carbon. Calculate the mass percent of chromium in...

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.

In: Chemistry

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

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.

In: Chemistry

Describe the nature of colloidal precipitate particles. (describe the electric double layer) ,Why do they tend...

Describe the nature of colloidal precipitate particles. (describe the electric double layer) ,Why do they tend to not settle, and What factors control coagulation of a colloidal particles?

In: Chemistry

Gas Laws Units in Gas Law Problems One problem associated with gas law problems is unit...

Gas Laws

Units in Gas Law Problems

One problem associated with gas law problems is unit agreement. It is important that pressure, volume and temperature units match or agree within a problem. Solve 1-4 using the factor-label method. Problems 5 and 6 are done without factor-label.

1. Convert 1.52 atm to kPa 2. Convert 85 kPa to mmHg

3. Convert 156.3 mmHg to atm 4. Convert 950 torr to kPa

5. Convert -250.0 °C to K 6. Convert 253 K to °C

Boyle’s Law

7. Equation for Boyle’s Law:

8. A gas occupies 12.3 L at 825.7 mmHg. What will the pressure be when the volume is 75 L?

9. A gas occupies 25 L at 2.5 atm. What is the volume if the pressure changes to 1.5 atm?

10. You have 50 L of CO2 gas at standard temperature and pressure (STP). What would need to be done to the pressure to cut the volume of gas in half?

Charles’ Law

11. Equation for Charles’ Law:

12. How do these two factors relate to each other?

13. What does temperature actually measure?

14. At 27.8 °C, a gas occupies 1500 m. What volume will it have at 100.0 °C?

15. What temperature (in K) must a gas be if it occupied 1.396 L at 72.3 °C and now occupies 1.044 L?

Gay-Lussac’s Law

16. Equation for Charles’ Law:

17. A gas cylinder contains nitrogen gas at 10-atm pressure and a temperature of 20˚C. The cylinder is left in the sun, and the temperature of the gas increases to 50˚C. What is the pressure in the cylinder?

18. A bike tire has a volume of 0.850L at a pressure of 40 psi and 0˚C. What will be the pressure of the tire at 35˚C?

19. An aerosol can has a fixed volume of gas at 4.0-atm of pressure and room temperature (25˚C). If the pressure inside the can reaches 5.9-atm the can will explode. The can is thrown into a fire that is 400˚C. Will the can explode? Show all calculations to support your answer.

In: Chemistry