Explanation:
a) Using Beer-Lambert's law :
Formula used :
where,
A = absorbance of solution = 0.945
c = concentration of solution = ?
l = length of the cell = 1.20 cm
= molar absorptivity of this solution =
(
)
14.16 μM is the molarity of the red dye solution at the optimal wavelength 519nm and absorbance value 0.945.
b) 
1 L of solution contains 
moles of red dye.
Mass of moles of red dye:
c) In order to dilute red dye solution by 5 times, we will need to add 1 L of water to solution of given concentration.
Concentration of red dye solution = 
Concentration of red solution after dilution = c'
The final concentration of the diluted solution is 
Answer:
6.1%
Explanation:
Assuming pressure inside balloon remains constant during the temperature change.
Therefore, as per Charles' law at constant pressure,
Percentage change in volume
Change in volume of the balloon is 6.1%
Therefore option c , i.e. The substances in both test tubes are reactive only at high temperatures. is the only statement which is NOT supported by the student's observations.
<h3>What is the reaction between Magnesium and Hydrogen ?</h3>
Magnesium reacts with hydrochloric acid to produce hydrogen gas
Mg (s) + 2 HCl (aq) → MgCl₂ (aq) + H₂ (g)
In this reaction, the magnesium and acid are gradually used up , which can be seen in the test tube 2 .
A chemical reaction is taking place in Test tube 2 ,
Hydrogen gas is released in test tube 2 ,
Energy is released in the reaction involving hydrochloric acid and we can see in test tube 2 the reaction is going on
therefore option C i.e. The substances in both test tubes are reactive only at high temperatures. is the only statement which is NOT supported by the student's observation.
To know more about the chemical reaction between Magnesium and Hydrogen and this test.
brainly.com/question/19062002
#SPJ4
Answer:
18.9 moles of MgCl2 = 17.834 kg of MgCl2
Explanation:
The molecular weight of MgCl is 80.0 g/mol . So, to convert the given mole amount to grams, multiply this by this number, which is constant for all compounds with a specific composition (mass fraction).
Considering the original question was in the context of chemistry, I wanted to make it seem formal and more educational too. Hopefully that worked!
EDIT: Came up with some text around what happens inside cells that would have made it better if someone just had an issue converting units, but I doubt my answer will be accepted >.<
The heat absorbed by the water that evaporates from the body is the so called latent vaporization heat of water.
The standard latent vaporization heat of water is 2,264.705 kJ / kg.
So, you just have to divide 125 kJ / 2,264.705 kJ/kg = 0.0552 kg = 55.2 g
Answer: 55.2 g
