What is the current and direction of flow in an ionic solution?

In summary, when a current passes through a solution of sodium chloride, 2.68 x 10^16 Na+ ions and 3.92 x 10^16 Cl- ions arrive at the negative and positive electrodes, respectively, in 1.00 second. The current passing between the electrodes can be calculated using the equation I = Q/t and is approximately 10.6 milliamperes. The direction of the current is towards the negative electrode, as conventional current is defined as a flow of positive charge. In order for an electric field to act on the negatively charged electrons inside a conducting wire, the charge density on the surface of the wire must be nonuniform.
  • #1
cse63146
452
0

Homework Statement



Current passes through a solution of sodium chloride. In 1.00 second, 2.68 x 10^16 Na+ ions arrive at the negative electrode and 3.92 x 10^16 Cl- ions arrive at the positive electrode.

What is the current passing between the electrodes?
Express your answer in milliamperes to three significant figures.

Part B

What is the direction of the current?
~away from the negative electrode or
~toward the negative electrode

Homework Equations



I = Q/t

The Attempt at a Solution




the difference between 2.68x10^16 and 3.92x10^16 as a Na+ ion and Cl- ion carry precisely one electric charge each, and the charge of an electron is 1.60 x 10^-19 C

I = Q/t
I = (1.60 x 10^-19 )/1
I = 1.60 x 10^-19 A = 1.60 x 10^-16 mA

am I right?

Part B

Conventional current was defined early in the history of electrical science as a flow of positive charge, so it would be towards the negative electrode?
 
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  • #2
So for part A, the net positive charge would be q = Ne = (Cl - Na)e = (1.24x10^16)(1.6x10^-19) = 1.98 x 10^-3 and when I convert it to mA, I get 1.984, but it says it's wrong. Any ideas?
 
  • #3
how did u do dat ? I am really confused with dis question
 
  • #4
You are correct with the direction of the current. Conventional current would flow toward the negative electrode.

For part a) I also get 1.984mA. You have said you want the answer to be in three significant figures, but 1.984mA has 4 significant figures. Could this be why it is being labeled as wrong? (I assume this is a computer based question?)
 
  • #5
ravi1611 said:
how did u do dat ? I am really confused with dis question

G01 said:
You are correct with the direction of the current. Conventional current would flow toward the negative electrode.

For part a) I also get 1.984mA. You have said you want the answer to be in three significant figures, but 1.984mA has 4 significant figures. Could this be why it is being labeled as wrong? (I assume this is a computer based question?)

I figured out the problem. I wasnt supposed to subtract the number of Na+ ions from the Cl- ions, I was supposed to add them together, and I would get 6.6 x 10^16 which I would multiply it by the charge of an electron, and once I convert it to mA, I get 10.6mA.

If the problem was too many significant digits, masteringphysics (the computer based website problem) would still give me the marks saying I just rounded it differently.

Thanks for everyone's help.
 
  • #6
cse63146 said:
I figured out the problem. I wasnt supposed to subtract the number of Na+ ions from the Cl- ions, I was supposed to add them together.

AHHH! Yes, I made the same mistake, don't feel too bad about it! Sorry if my mistake mislead you in any way.
 
  • #7
What quality must the charge density on the surface of a conducting wire possesses if an electric field is to act on the negatively charged electrons inside the wire?

The charge density must be
positive.
negative.
nonuniform.
uniform.can anybody please help with dis..i think its uniform but I am not sure
 
  • #8
G01 said:
AHHH! Yes, I made the same mistake, don't feel too bad about it! Sorry if my mistake mislead you in any way.

It's okay; I got the answer before you posted, and I'll prefer to do this on an assigment worth about 1% than a test any day

and ravi1611, the answer is nonuniform
 
Last edited:
  • #9
thx alot
 

What is an ionic solution?

An ionic solution is a type of liquid solution that contains ions, which are charged particles. These ions can be either positively or negatively charged, and they are formed when an ionic compound, such as a salt, is dissolved in a liquid solvent, such as water.

How does current flow in an ionic solution?

Current in an ionic solution is carried by the movement of ions. When an electrical potential is applied across the solution, the positively charged ions, called cations, move towards the negative electrode and the negatively charged ions, called anions, move towards the positive electrode. This movement of ions creates an electric current.

What factors affect the current in an ionic solution?

The current in an ionic solution is affected by several factors, including the concentration of ions in the solution, the distance between the electrodes, the temperature of the solution, and the strength of the electric field applied. Higher ion concentration, shorter distance between electrodes, higher temperature, and stronger electric field all result in higher current.

How is current in an ionic solution measured?

The current in an ionic solution is typically measured using an ammeter, which is a device that measures the flow of electric current in a circuit. The ammeter is connected in series with the circuit and measures the current passing through it. The unit of measurement for current is amperes (A).

What are some real-world applications of current in an ionic solution?

Current in an ionic solution has many practical applications, including electroplating, which uses an ionic solution to coat one metal with another; batteries, which use ionic solutions to store and release energy; and fuel cells, which use ionic solutions to convert chemical energy into electrical energy. It is also used in various industrial processes, such as wastewater treatment and metal refining.

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