kesh kesh

what are some sources of error in an electrochemical cell experiment?

Regarding feedback inhibition, which of the following statements is true?

1. The substrate of the reaction stimulates the reaction by binding into an enzyme's catalytic site.

2. All of the answers above are incorrect.

3. The substrate of the reaction inhibits the reaction by binding into an enzyme's allosteric site.

4. The end product of the reaction stimulates the reaction by binding into an enzyme's allosteric site.

5. The end product of the reaction inhibits the reaction by binding into an enzyme's catalytic site.

Which is not correct when describing the process of chemiosmosis?

1. The NADH dehydrogenase complex donates electrons to a molecule called flavin mononucleotide (FMN).

2. Respiration (through chemiosmosis) and fermentation (through substrate level phosphorylation) are two independent ways of generating ATP.

3. Chemiosmosis involves molecules called cytochromes that are generally found in the inner (plasma) membrane of bacteria and of mitochondria.

4. The electron transport chain refers to the "donation" of electrons from NADH dehydrogenase to ATP synthase via cytochromes

what would the initial concentration of NH3 be if its a .2M mole solution and theres .5 ml of it

can someone please tell me what the name of the font is used in this picture? thank you

http://www.charmcitytrivia.com/img/BeerPongChampio...

Two long, straight parallel wires are 10.0 cm apart and carry 3.20 A currents in the same direction

1. Find the magnitude of the magnetic field at point P1, midway between the wires

2. Find the magnitude of the magnetic field at point P2, 29.0 cm to the right of P1

Which of the following statements about radio waves, infrared radiation, and x rays are correct? (There may be more than one correct choice.)

A. They all have the same wavelength in vacuum.

B. They all have the same frequency in vacuum.

C. They all have exactly the same speed as visible light in vacuum.

D. The short-wavelength x rays travel faster through vacuum than the long-wavelength radio waves.

Light having a certain frequency, wavelength, and speed is traveling through empty space.

1. If the frequency of this light were doubled, then...

A.its wavelength would remain the same, but its speed would double.

B. its wavelength would remain the same, but its speed would be halved.

C.its wavelength would be halved, but its speed would double.

D.its wavelength would be halved, but its speed would remain the same.

E. both its speed and its wavelength would be doubled.

You want to produce a magnetic field of magnitude 5.50×10^−4 T at a distance of 4.00×10^−2 m from a long, straight wire.

1. What current is required to produce this field?

2. With the current found in part (A), how strong is the magnetic field 8.00 cm from the wire’s center?

In a cloud chamber experiment, a proton enters a uniform 0.340 T magnetic field directed perpendicular to its motion. You measure the proton's path on a photograph and find that it follows a circular arc of radius 6.30 cm.

1. How fast was the proton moving?

An ion having charge +6 is traveling horizontally to the left at 8.50 km/s when it enters a magnetic field that is perpendicular to its velocity and deflects it downward with an initial magnetic force of 6.94×10^−15 N

1. What is the direction of this field?

a. out of the page

b. into the page

c. to the left

d. to the right

2. What is the magnitude of this field?

2B9s) +3H2(g) --> B2H6 (g)

1. If .225 moles of boron are reacted in a 6.00 L container containing an excess (4.50 atm) of hydrogen at 55 degrees Celcius what is the total pressure in the vessel when the reaction is complete?

A. 3.49 atm

B. 2.99atm

C. 5.00 atm

D. 4.50 atm

E. 2.14 atm

PLEASE SHOW YOUR WORK

1. a system that does no work but which receives heat from the surroundings has...

A. q <, change in E>0

B. q>0, change in E<0

C. q=change in E

D.q=negative change in E

E.w=change in E

2. predict whether the products of a reaction of aqueous sodium hydroxide and aqueous phosphoric acid are endotheric, exothermic and the sign of q

A exothermic, q>0

B endothermic, q>0

C exothermic q<0

D endothermic, q<0

E endothermic q=0

the amount of energy required to excite a CO molecule from n=1 to the first excited state is 46.3 J/mol. Calculate the wavelength of lightt in nm that provides this amount of energy

A. 4.29 x 10 ^5 nm

B. 1.28 x 10^3 nm

C. 3.27 x 10^2 nm

D. 7.93 x 10^5 nm

E. 2.59 x 10^6 nm

PLEASE SHOW YOUR WORK

Two point charges are placed on the x axis as follows: Charge q1 = 4.00nC is located at x = 0.200m and charge q2 = 5.00nC is at x = -0.300m.

What are the magnitude and direction of the net force exerted by these two charges on a negative point charge q3 = -0.600nC placed at the origin?

A point charge +Q1 exerts an electrostatic force F on a point charge +Q2 that is 6.00cm away.

If the charges are now placed 12.0cm apart, the electrostatic force that Q1 exerts on Q2 will be

F.

F/2.

F/4.

F/36.

Three equal point charges are held in place.

If F1 is the force on q due to Q1 and F2 is the force on q due to Q2, how do F1 and F2 compare?

F1=2F2

F1}=3F2

F1=4F2

F1=9F2

At what distance would the repulsive force between two electrons have a magnitude of 3.50N? between 2 protons?

Trial 1: 24.926 mL

Trial 2: 24.915 mL

Trial 3: 24.941mL

The above is an example of how an instrument ( in this case a pipet) can be calibrated. We expected the volume to be 25,00mL, but the actual volume was significantly less. If you had measured the density of an unknown with this pipet and assumed that V= 25.00mL, your result would not be correct. Would it be too high or too low? Explain

You are designing a hydraulic lift for an automobile garage. It will consist of two oil-filled cylindrical pipes of different diameters. A worker pushes down on a piston at one end, raising the car on a platform at the other end. To handle a full range of jobs, you must be able to lift cars up to 3000kg , plus the 600kg platform on which they are parked. To avoid injury to your workers, the maximum amount of force a worker should need to exert is 100N .

1. What should be the diameter of the pipe under the platform?

Water is flowing in a cylindrical pipe of varying circular cross-sectional area, and at all points the water completely fills the pipe.

1.At a second point in the pipe, the water speed is 3.80 . What is the radius of the pipe at this point?