Answer:
Explanation:
Assuming that you are asking for the full-balanced equations...
2Na + O2 = Na2O2
H2 + O2 = H2O2; This equation is already balanced, there is no need for change.
Please let me know if this is not the answer you are looking for and I will amend the answer.
Answer : The mass of helium gas added must be 12.48 grams.
Explanation : Given,
Mass of helium (He) gas = 6.24 g
Molar mass of helium = 4 g/mole
First we have to calculate the moles of helium gas.

Now we have to calculate the moles of helium gas at doubled volume.
According to the Avogadro's law, the volume of gas is directly proportional to the number of moles of gas at same pressure and temperature. That means,

or,

where,
= initial volume of gas = V
= final volume of gas = 2V
= initial moles of gas = 1.56 mole
= final moles of gas = ?
Now we put all the given values in this formula, we get


Now we have to calculate the mass of helium gas at doubled volume.


Therefore, the mass of helium gas added must be 12.48 grams.
Answer:
The answer is
<h2>1.74 g/mL</h2>
Explanation:
The density of a substance can be found by using the formula

From the question
mass of magnesium = 11.81 g
volume = 6.80 mL
The density of the metal is

We have the final answer as
<h3>1.74 g/mL</h3>
Hope this helps you
The answer is D. A compound
Answer is: <span>he boiling point of a 1.5 m aqueous solution of fructose is </span>100.7725°C.
The boiling point
elevation is directly proportional to the molality of the solution
according to the equation: ΔTb = Kb · b.<span>
ΔTb - the boiling point
elevation.
Kb - the ebullioscopic
constant. of water.
b - molality of the solution.
Kb = 0.515</span>°C/m.
b = 1.5 m.
ΔTb = 0.515°C/m · 1.5 m.
ΔTb = 0.7725°C.
Tb(solution) = Tb(water) + ΔTb.
Tb(solution) = 100°C + 0.7725°C = 100.7725°C.