Discussion about: Fertilizers

Fertilizers and pesticides are chemicals that have been used by homeowners and farmers to produce greener lawns and larger crops. These chemicals are proved to be harmful to humans and animals health. Some people don't eat food that was harvested from plants where fertilizers and other toxic chemicals were used, they like to consume "Organic Produces" only. What do you think from a scientific point of view? Do you agree with those who eat "Organic Produces" only and why? or why not?

PLEASE MAKE SURE TO TYPE THE ANSWER CLEARLY.

Best Regards,

A sample of water with a Fe2+ concentration of 500 ppm. Additionally Eh is 0.503 V and pH is 3.45. Will Fe(OH)3(s) stay in solution? What would be the equilibrium Eh at this pH?

Hydrofluoric acid, HF, has a K a of 6.8 × 10í. What are [H3O+ ], [Fí ], and [OHí ] in 0.790 M HF?

[H3O+] = (unrounded)

[F ] = M

[OHí ] = (Enter your answer in scientific notation.)

Find PH of solutions from list below

Bottle A : 200ml of 0.0750 M hcl (aq)

Bottle B: 200ml of 0.200 M methylamine (CH3NH2, PKb=3.36, molar mass = 31.0)

Bottle C 100g of solid Methylamine Hydrochloride ( Molar mass = 67.5)

a) Solution 1: 6.75 g of solid in bottle c dissolved in water to make 500 ml solution

b) solution 2: Mix 75 ml of solution 1 with 75 ml of bottle b

c) solution 3: Mix 15.0 ml of bottle a and 50 ml of solution 2

Please answer all three thank you!

Part A

To what volume should you dilute 155 mL of an 8.60 M CuCl2 solution so that 60.0 mL of the diluted solution contains 5.9 g CuCl2? Answer in mL

Part B

What is the molarity of an aqueous solution that is 5.69 % NaCl by mass? (Assume a density of 1.02 g/mL for the solution.)

Part C

Ocean water contains 3.5 % NaCl by mass. How much salt can be obtained from 304 g of seawater? Express your answer using two significant figures.

In a study, 2-MeV neutrons enter a target made of water and are gradually absorbed in the water.

Assume:

1. The neutrons don't interact with oxygen

2. Their capture cross section before they thermalize is 2.5 barns.

Calculate (for the neutrons):

a. Mean free path.

b. Linear momentum as they the target.

c. Velocity as they enter the target.

d. Calculate the neutron's lifetime in the medium (average time before they are captured).

Indicate all units.

A 0.9000 g sample of a mixture of NaCl and KCl is dissolved in water, and the solution is then treated with an excess of AgNO₃ to yield 1.923 g of AgCl. Calculate the percent by mass of each compound in the mixture.

____% mass of NaCl

____% mass of KCl

a) Calculate the change in entropy on heating an ideal gas from 300K to 500K at constant pressure.

b) Calculate the change in entropy on heating an ideal gas from 300K to 500K at constant volume.

c) why these answers are different.

Please explain each steps.

What additives may be used to prevent acid catalyzed hydrolysis of drugs containing ester moieties in drug formulations?

Please answer:
Discuss how many anions are able to contaminate groundwater.

Menthol is a crystalline substance with a peppermint taste and odor. When 1.19 g of menthol is dissolved in 25.0 g of cyclohexane, the freezing point of the solution is lowered by 6.34 ∘ C. Look up the freezing point and K f constant for cyclohexane in the Colligative Constants table. Calculate the molar mass of menthol.

Imagine two solutions with the same concentration and the same boiling point, but one has ethanol as the solvent and the other has carbon tetrachloride as the solvent. Determine that molal concentration, m (or b),m (or b), and boiling point, Tb.Tb.

m=

Tb=

Firefly luciferase is the enzyme that allows fireflies to illuminate their abdomens. Because this light generation is an ATP-requiring reaction, firefly luciferase can be used to test for the presence of ATP. In this way, luciferase can test for the presence of life. The coupled reactions are

1.2.luciferin+O2ATP⇌⇌oxyluciferin+lightAMP+PPiΔG∘=−31.6 kJ/mol

If the overall ΔG∘ of the coupled reaction is -5.50 kJ/mol , what is the equilibrium constant, K, of the first reaction at 23 ∘C ?

This is a physical chemistry question.

Write down for yourself the secular determinant for the hypothetical molecule linear H₃ making the Huckel approximation, using the 1s atomic orbitals from each atom as the basis set. Given that α=-2.00 eV and β= -2 eV, what is the total electronic energy in eV?