Answer: Noble-gas notation of Sn contains Kr.
Explanation: Tin ( Sn) is an element having atomic number 50.
Nearest noble gas to this element is Krypton which has an atomic number 36.
Electronic configuration or noble-gas notation for Sn is written as :
![Sn=[Kr]4d^{10}5s^25p^2](https://tex.z-dn.net/?f=Sn%3D%5BKr%5D4d%5E%7B10%7D5s%5E25p%5E2)
As seen from above, Noble gas Krypton having symbol 'Kr' is coming in the electronic configuration for Tin.
The amount of energy in kilocalories released from 49 g of glucose given the data is -4.4 Kcal
How to determine the mole of glucose
Mass of glucose = 49 g
Molar mass of glucose = 180.2 g/mol
Mole of glucose = ?
Mole = mass / molar mass
Mole of glucose = 49 / 180.2
Mole of glucose = 0.272 mole
How to determine the energy released
C₆H₁₂O₆ →2C₂H₆O + 2CO₂ ΔH = -16 kcal/mol
From the balanced equation above,
1 mole of glucose released -16 kcal of energy
Therefore,
0.272 mole of glucose will release = 0.272 × -16 = -4.4 Kcal
Thus, -4.4 Kcal were released from the reaction
Learn more about stoichiometry:
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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.
Mixture is physical, compound is chemical, and a element is the base version
Answer is: there is 0,592 moles of CF₂Cl₂.
m(CF₂Cl₂) = 71,66 g.
n(CF₂Cl₂) = m(CF₂Cl₂) ÷ M(CF₂Cl₂).
n(CF₂Cl₂) = 71,66 g ÷ 120,91 g/mol.
n(CF₂Cl₂) = 0,592 mol.
M - molar mass substance.
m - mass of substance.
n - amount of substance.