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dlinn [17]
3 years ago
15

What is cold source of light

Chemistry
2 answers:
Anettt [7]3 years ago
6 0
Fireflies. LED, fluorescent light
jekas [21]3 years ago
4 0

Answer:

LEDs (they can heat up, but they do not require heat to emit light, usually heat is an unwanted effect)

Light-emitting field-effect transistors (same consideration as for LEDs)

Fluorescent lighting and generally cold plasmas that can emit light.

Old TV and PC monitors (ie cathode ray tube screen - although the light emission itself does not require heat, the cathode itself that shoots the electrons does)

Chemo-luminescence (like fluorescent sticks)

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The spontaneous reaction that occurs when the cell in the picture operates is as follows: 2Ag+ + Cd(s) ???? 2 Ag(s) + Cd2+ (A) V
Snowcat [4.5K]

Answer:

14. B    15. D    16. C     17. B

Explanation:

The spontaneous reaction that occurs when the cell operates is shown below:

2Ag^{+} + Cd_{(s)} ⇒2Ag_{(s)} + Cd^{2+}

We need to select the correct option from the list below for the following questions.

(A) Voltage increases. (B) Voltage decreases but remains > zero. (C) Voltage becomes zero and remains at zero. (D) No change in voltage occurs. (E) Direction of voltage change cannot be predicted without additional information.

14. A 50-milliliter sample of a 2-molar Cd(NO_{3})_{2} solution is added to the left beaker.

If a 50-milliliter sample of a 2-molar Cd(NO_{3})_{2}  solution is added to the left beaker, the voltage decreases but its value remains greater than zero. The correct option is B

15. The silver electrode is made larger.

If the silver electrode is made larger, no change in the value of the voltage since we don't have the idea of the initial value. The correct option is D.

16. The salt bridge is replaced by a platinum wire.

If the salt bridge is replaced by a platinum wire, there will be no passage of electrons because electrons can't pass through a platinum wire. Therefore, the voltage will be zero and remains at zero. The correct option is C.

17. Current is allowed to flow for 5 minutes.

If current is allowed to flow for 5 minutes, the voltage decreases but its value remains greater than zero. The correct option is B.

7 0
3 years ago
Determine the molar mass of CuSO4×5H2O
asambeis [7]
248.72 g/mol

CuSO4 has a molar mass of 159.62. H2O has a molar mass of 18.02, which is multiplied by 5 to reflect the 5 H2O molecules.

159.62+5(18.02)=249.72 g/mol
7 0
3 years ago
The density of benzene at 15 °c is 0.8787 g/ml. Calculate the mass of 0.1500 l of benzene at this temperature. Enter your answer
Otrada [13]

Answer:

131.8 g.

Explanation:

  • There is a relation that relates the density of the substance (d) to the mass (m) and the volume of the substance (V):

<u><em>d = m / V.</em></u>

d = 0.8787 g/ml.

V = 0.15 L x 1000 = 150 ml.

  • ∴ the mass of 0.15 L of benzene = d x V = (0.8787 g/ml) (150 ml) = 131.8 g.
5 0
3 years ago
A jar is filled with water, and the lid is closed tightly. The jar is kept at constant temperature. What happens at the surface
Katarina [22]
<h2>Hello!</h2>

The correct answer is A: Water molecules evaporate and condense at the same rate.

<h2>Why?</h2>

Evaporation is defined as the physical change from liquid to gas, and Condensation is the physical change from gas to liquid.

At any given temperature, these two processes occur at once, in a dynamic equilibrium.

When the lid is closed, evaporation occurs faster than condensation, and pressure increases. Then, when pressure reaches a critical value, condensation starts to occur faster than evaporation, until an equilibrium is reached, and the pressure of the water molecules in the gas phase is maximum for that temperature. The pressure at that point is called Vapor Pressure.

Have a nice day!

5 0
3 years ago
I need more help with science again
Sloan [31]
Membranes are barriers and “gatekeepers”, they only let certain molecules pass through them.

they also transport nutrients to the cell
5 0
3 years ago
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