Answer : The mass of oxygen formed must be 3.8 grams.
Explanation :
Law of conservation of mass : It states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.
This also means that total mass on the reactant side must be equal to the total mass on the product side.
The balanced chemical reaction will be,

According to the law of conservation of mass,
Total mass of reactant side = Total mass of product side
Total mass of
= Total mass of 
As we are given :
The mass of
= 25.3 grams
The mass of
= 23.4 grams
So,



Therefore, the mass of oxygen formed must be 3.8 grams.
Answer : The change in boiling point is, 
Explanation :
Formula used :

where,
= change in boiling point = ?
i = Van't Hoff factor = 3 (for MgI₂ electrolyte)
= boiling point constant for water = 
m = molality = 0.615 m
Now put all the given values in this formula, we get


Therefore, the change in boiling point is, 
Answer:
140 K
Explanation:
Step 1: Given data
- Initial pressure of the gas (P₁): 3 atm
- Initial temperature of the gas (T₁): 280 K
- Final pressure of the gas (P₂): 1.5 atm
- Final temperature of the gas (T₂): ?
Step 2: Calculate the final temperature of the gas
We have a gas whose pressure is reduced. If we assume an ideal behavior, we can calculate the final temperature of the gas using Gay-Lussac's law.
T₁/P₁ = T₂/P₂
T₂ = T₁ × P₂/P₁
T₂ = 280 K × 1.5 atm/3 atm = 140 K
0.086mole
Explanation:
The problem is very simple. It involves conversion from mass to number of moles of NaCl
What is mole?
A mole is a unit of measuring chemical substances. It is the amount that contains the avogadro's number of particles.
How is it related and can be converted from mass;
Number of moles of a substance = 
Since we know the mass, we can find the molar mass and put into this equation;
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Number of moles of NaCl =
0.086mole
learn more:
Number of moles brainly.com/question/1841136
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