Electrons are emitted from the surface of a metal in photoelectric effect.
<h3>What is the photoelectric effect?</h3>
The photoelectric effect is the emission of electron from the surface of a metal when light is shone on the surface..
For electrons to be emitted, the light must have a certain frequency known as threshhold frequency.
Therefore, electrons are emitted from the surface of a metal in photoelectric effect.
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Concentration of unknown acid is 0.061 M
Given:
Concentration of NaOH = 0.125 M
Volume of NaOH = 24.68 mL
Volume of acid solution = 50.00 mL
To Find:
Concentration of the unknown acid
Solution: Concentration is the abundance of a constituent divided by the total volume of a mixture. The concentration of the solution tells you how much solute has been dissolved in the solvent
Here we will use the formula for concentration:
M1V1 = M2V2
0.125 x 24.68 = 50 x M2
M2 = 0.125 x 24.68 / 50
M2 = 0.061 M
Hence, the concentration of unknown acid is 0.061 M
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The answer is double displacement is the answer
Answer:
the activation energy Ea = 179.176 kJ/mol
it will take 7.0245 mins for the same food to cook in an open pot of boiling water at an altitude of 10000 feet.
Explanation:
From the given information



Thus; 
Because at 113.0°C; the rate is 7 time higher than at 100°C
Hence:

1.9459 = 



Ea = 179.176 kJ/mol
Thus; the activation energy Ea = 179.176 kJ/mol
b)
here;






where ;


Now;

t = 7.0245 mins
Therefore; it will take 7.0245 mins for the same food to cook in an open pot of boiling water at an altitude of 10000 feet.