My calculations say it'll take 600 hours???
The question is incomplete, complete question is :
A chemist must dilute 73.9 mL of 400 mM aqueous sodium carbonate solution until the concentration falls to 125 mM . He'll do this by adding distilled water to the solution until it reaches a certain final volume. Calculate this final volume, in liters. Be sure your answer has the correct number of significant digits.
Answer:
The final volume of the solution will be 0.236 L.
Explanation:
Concentration of sodium carbonate solution before dilution =
Volume of sodium carbonate solution before dilution = 
Concentration of sodium carbonate solution after dilution =
Volume of sodium carbonate solution after dilution = 
Dilution equation is given by:
1 mL = 0.001 L
236 mL = 0.236 L
The final volume of the solution will be 0.236 L.
Answer:
northwest
Explanation:
Cmon man adleast try before you ask it on brainly or else you will never get any smarter
To cool 156 g of water from 42.9 °C to 20.5 °C, 101 g of CF₂Cl₂ are required.
CF₂Cl₂ is a refrigerant. When it is evaporated, it absorbs heat from water, which cools.
<h3>What is evaporation?</h3>
Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase.
- Step 1: Calculate the heat released by water.
We will use the following expression.
Qw = c × m × ΔT = (4.184 J/g.°C) × 156 g × (20.5 °C - 42.9 °C)
Qw = -14.6 kJ
where,
- Qw is the heat released by water.
- c is the specific heat of water.
- m is the mass of water.
- ΔT is the change in the temperature of water.
If water releases 14.6 kJ of heat, CF₂Cl₂ absorbs 14.6 kJ of heat (Qr = 14.6 kJ).
- Step 2: Calculate the mass of the refrigerant required.
We will use the following expression.
Qr = ΔH°evap × m
m = Qr/ΔH°evap = 14.6 kJ / (0.144 kJ/g) = 101 g
where,
- Qr is the heat absorbed by the refrigerant.
- ΔH°evap is the heat of vaporization of the refrigerant.
- m is the mass of the refrigerant.
To cool 156 g of water from 42.9 °C to 20.5 °C, 101 g of CF₂Cl₂ are required.
Learn more about evaporation here: brainly.com/question/25310095
Answer:
The pattern of decay emission is visualized on X-ray film by auto-radiography.
Explanation:
The image on the x-ray are auto-radiography or the nuclear emission that has been produced as a result of the decay emission because of the gamma particles or the beta particles which comes from a radioactive substance. These auto-radiography are available as the digital image as a result of recent development of gas detectors or because of the rare earth phosphor imaging system. Some of the can be studied microscopically for silver granules this method is called as micro- auto-radiography.
