A beaker with 2.00×102 mL of an acetic acid buffer with a pH of 5.000 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 7.20 mL of a 0.450 M HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.740. Express your answer numerically to two decimal places. Use a minus ( − ) sign if the pH has decreased.

In general, how do you draw lewis structures? What are the steps and then how do you draw the structure based on what you are given? Sorry if this is confusing, I am very confused on how I draw the structure given a molecule etc.. This is for basic chemistry.

Use the link Standard Reduction Potentials to answer the following questions.
For each pair of redox couples, write a balanced redox equation, determine the cell potential and the number of electrons transferred. Use the lowest possible coefficients. Include states-of-matter in your answer.

1. 26 mol of P₄O₁₀ contains how many moles of P?

? mol P

2. How many moles of N are in 0.247 g of H₂O?

? mol N

3. How many total atoms are in 0.870 g of P₂O₅?

? atoms

1. Acetone

2. Water

3.Isopropyl alcohol

A. Rank the three liquids, from slowest rate to the highest rate of evaporation based on the expiremental temperature vs time curve?

B. How does the ranking in A compare to the ranking of the boiling points, from the lowest to highest?

C. How does the ranking in A compare to the ranking of the heats of vaporization, from lowest to highest?

D. Explain the above findings based on any differences between the substances sets of intermolecular interactions.

In the lab you were told that the hydrolysis of tert-butylchloride reacts via an S_N1 mechanism and your graphs were constructed assuming a first-order reaction. Describe how one can graphically determine whether a reaction is 1^st order or 2^nd order?

What is the mass (in grams) of 9.06 * 10²⁴ molecules of methanol (CH₃OH)?

18) The major sink(s) for Cl^- in the ocean is(are):

1. Formation of authigenic minerals
2. Consumption by hydrothermal activities
3. Consumption by reverse weathering
4. Reaction in sediment pore waters
5. All of above
6. a, b and c
7. a and d
8. b and c

19) The correct sequence in the concentration of cations in seawater is:

1. Ca²⁺> Na⁺ > Mg²⁺
2. Na⁺ > Ca²⁺ > Mg²⁺
3. Ca²⁺ < Na⁺ < Mg²⁺
4. Na⁺ > Mg²⁺ > Ca²⁺

20) The major sink(s) for Mg²⁺ in the ocean is(are):

1. Formation of authigenic minerals
2. Consumption by reverse weathering
3. Consumption by hydrothermal activities
4. Reaction in sediment pore waters
5. All of above

21) The correct sequence in the concentration of anions in seawater is:

1. Cl^- > SO₄^2- > HCO₃^-
2. SO₄^2- > Cl^- > HCO₃^-   
3. Cl^- > HCO₃^- > SO₄²
4. Na⁺ > Cl^- > HCO₃

22) The major sink(s) for Na⁺ in the ocean is(are):

1. Consumption by reverse weathering
2. Formation of authigenic minerals
3. Consumption by hydrothermal activities
4. Reaction in sediment pore waters
5. all of above
6. a and b
7. a and c
8. b and c
9. a and d

23) The major sink(s) for K⁺ in the ocean is(are):

1. Consumption by hydrothermal activities
2. Formation of authigenic minerals
3. Consumption by reversing weathering
4. Reaction in sediment pore waters
5. All of above
6. a, b and d
7. a, c and d
8. b, c and d

24) The correct sequence in oceanic residence time is:

1. HCO₃^- > SO₄^2- > Cl^-
2. SO₄^2- > Cl^- > HCO₃^-
3. HCO₃^- < SO₄^2- < Cl^-

25) If water residence time in the ocean is 20,000 years, an element with a seawater to river water concentration ratio of 0.5 has a oceanic residence time of:

1. 80,000 yr
2. 40,000 yr
3. 20,000 yr
4. 10,000 yr

26) The major sink(s) for HCO₃^- supplied to the ocean by river runoff is(are):

1. Reaction in sediment pore waters
2. Consumption by reversing weathering
3. Consumption by hydrothermal activities
4. Formation of authigenic minerals
5. All of above
6. a and b
7. b and c
8. b and d

27) If water residence time in the ocean is 40,000 years, an element with a seawater to river water concentration ratio of 1.5 has a oceanic residence time of:

1. 80,000 yr
2. 60,000 yr
3. 40,000 yr
4. 10,000 yr

Coke can be converted into CO�a fuel gas�in the reaction CO2 (g) + C (s) ? 2 CO (g) a coke that contains 84% carbon by mass and the balance noncombustible ash is fed to a reactor with a stoichiometric amount of CO2. The coke is fed at 77�F, and the CO2 enters at 400�F. Heat is transferred to the reactor in the amount of 5859 Btu/lbm coke fed, the gaseous products and the solid reactor effluent (the ash and unburned carbon) leave the reactor at 1830�F. The heat capacity of the solid is 0.24 Btu/(lbm?�F). (a) Calculate the percentage conversion of the carbon in the coke. (b) The carbon monoxide produced in this manner can be used as a fuel for residential home heating as can the coke. Speculate on the advantages and disadvantages of using the gas.

10.33 predict the shape or geometry of the following mol-ecules , using theVSEPR model

A). SiF₄

B). SF₂

C) CoF₂

D) PCl₃

What is the evaporated volume of one pint of liquid methanol (MW=46.1, SG=0.79) at standard temperature and pressure?

A student uses a volumetric pipet calibrated to deliver exactly 50.0mL of a liquid and then measures the mass of the liquid. how is the density determination of the liquid affected in the situations which follow? Would the density increase, decrease, or not be affected? Explain your answers

a. dirty pipet is used and water droplets adhere to the inner walls of the pipet

b. the student did not allow sufficient time for all the liquid to empty from the pipet

c. the student blew out all the liquid from the pipet, including the small amount from the tip.

d. the student did not remove air bubbles from the pipet before delivering the liquid

e. after mark on the pipet, the student didn't read the upper edge of the meniscus, not the lowest point on the Curve.

What amount of HCl gas must be added to 1.00L of a buffer solution that contains [aceticacid]=2.0M and [acetate]=1.0M in order to produce a solution with pH= 4.19?