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?

How many grams of dipotassium succinate trihydrate (K2C4H4O4·3H2O, MW = 248.32 g/mol) must be added to 800.0 mL of a 0.0524 M succinic acid solution to produce a pH of 5.969? Succinic acid has pKa values of 4.207 (pKa1) and 5.636 (pKa2).

* I unerstand this is a chemical engineering question but that was not a subject choice *

Using the information in Perry's Chemical Engineer's Handbook, compute the Henry's law constant in atm for nitrogen in water at 299.0 degrees Kelvin.

I have access to the values in Perry's Chemical Engineering Handbook, I just have absolutely no idea how to solve this.

A. What mass of carbon dioxide is produced from the complete combustion of 3.30×10−3 g of methane?

B. What mass of water is produced from the complete combustion of 3.30×10−3 g of methane?

C. What mass of oxygen is needed for the complete combustion of 3.30×10−3 g of methane?

Can someone that lives in a home with smokers develop breathing problems from second hand smoke. I am writing a paper on this topic, i could use any feedback

a. In general is there any difference between R and S, and + and -? between d- and l-, and + and -?

b. Discuss the validity of the following statements:

        1. A mixture of (+)- and (--)-carvone can be separated by column chromatography on silica gel using hexanes-acetone as elution.

        2. In general, column chromatography on silica gel is run with a series of solvents of increasing polarity.

        3. Carvone is more polar than limonene.

c. Which compound, limonene or carvone, do you expct would elute first from the silica gel column? Which one would have shorter retention time on the GC? Briefly justify your answer.

True or False:

A. When atoms bond covalently energy is released

B. All the carbon to carbon bonds in benzene are the same.

C. A mole of NH3 and a mole of H2O weigh the same.

D. ice is denser than liquid water.

E. In organic compounds C atoms have 4 covalent bonds.

F. Water is a nonpolar compound.

G. Diamond, graphite, and fullerene are all forms of carbon.

H. All spontaneous chemical reactions are exothermic.

I. C4H8 is a saturated compound

J. When liquid water freezes heat is liberated.

1) Calculate the enthalpy of reaction (ΔHrxn) for the following reaction:

Fe2O3(s) + 3 CO(g) → 2 Fe(s) + 3 CO2(g)

Given: 4 Fe(s) + 3 O2(g) → 2 Fe2O3(s) ΔH = –1648 kJ 2 CO2(g) → 2 CO(g) + O2(g) ΔH = +565.4 kJ

2) Use standard enthalpies of formation to calculate the standard enthalpy of reaction for the following reaction:

2 H2S(g) + 3 O2(g) → 2 H2O(l) + 2 SO2(g) ΔH∘rxn

For the eight reactions done in test tubes, explain your observations in terms of mechanism (SN1 or SN2) , expected intermediates (carbocation or a single step conversion) and product. When they react with Sodium iodine in acetone and Silver nitrate in ethanol. 1. 1-Cholorbutane 2. 1-bromobutane 3. 2-Chlorobutane 4. 2- Chloro-2-Methyl Propane 5. Bromobutane 6. 2-Bromobutane 7. 2-Bromo-2-Metylpropane 8. 1-Chloro-2-Methyl Propane