Answer is: mass of sodium nitrate is 21,25 g.
m(H₂O) = 500 g · 1 kg/1000 g = 0,5 kg.
b(solution) = 0,500 m = 0,500 mol/kg.
m(NaNO₃) = ?
b(solution) = n(NaNO₃) ÷ m(H₂O).
n(NaNO₃) = 0,500 mol/kg · 0,5 kg.
n(NaNO₃) = 0,25 mol.
m(NaNO₃) = n(NaNO₃) · M(NaNO₃).
m(NaNO₃) = 0,25 mol · 85 g/mol.
m(NaNO₃) = 21,25 g.
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The relative volumes of chloroform and water that should be used is 9:10
Concentration of solution in chloroform =
( moles of chloroform )
Concentration of solution in water =
( moles of water )
Dissociation constant at
; 
Concentration of solution in chloroform / Concentration of solution in water
Meaning;

Since
mole is present in chloroform and
mole is present in water, Total mole of Caffeine present is 
Now, we substitute our given values into the equation

Therefore, the relative volumes of chloroform and water that should be used is 9:10
Learn more; brainly.com/question/11060225
Noble gas configuration for Li : [He]2s¹
<h3>Further explanation
</h3>
In an atom, there are levels of energy in the shell and sub-shell
This energy level is expressed in the form of electron configurations.
Lithium with atomic number 3, then the electron configuration:
1s²2s¹
And for noble gas configuration or it can be called Condensed electron configurations :
[He]2s¹
Answer:
The organs present inside the chest are :
1. The lungs
2. The heart
Explanation:
The chest cavity is also called as the thoracic cavity. It is the second largest hollow space of the body.In the bottom , it is enclosed by the diaphragm.
This cavity actually contain three space each round with mesothelium , pleural cavity and precardial cavity.
This contain the lungs , the tracheobronchial tree , the heart , the blood vessels which transport the blood between the heart and the lungs.
It also contain the esophagus .
Esophagus is the path through which the food passes from the mouth to the stomach.