<span>The chemical formula of Helium is He.
Question 1 :
Given n = 1.11 x 10^-6
To get no. of the particle,
No of particle = no. of mole x Avogadro Constant
p = n x NA
1 mol of Helium = 6.02 x 10^23
No of atoms = (6.02 x 10^23) x (1.11 x 10^-6)
= 6.66 x 10^17
................................
Question 2 :
Given p = 4.29x10^21
p = n x NA
4.29 x 10^21 = n x (6.02 x 10^23)
(4.29 x 10^21) / (6.02 x 10^23) = n
n = Approximately 7.126 x 10^-3
Hope the answer is right :)</span>
Answer:
Explanation:
Isotopes are atoms of elements that have the same atomic number but different mass number hence ISOTOPY. Radioactive Isotopes on the other hand are unstable as they either undergo Alpha decay, beta decay or gamma decay compared to stable isotopes.
Radioactive elements decay at varyinf rates as such the rate of radioactive decay is used in the characterization of radioactive element and mostly expressed in terms of the half life of the radioactive elements.
Half life is the time taken for half of the total atoms of an elements to decay into half of its initial sizes. for example, the half life of radium-226 is 1622 years, it implies that if we have 1000000 radium atoms at the beginning, then at the end of 1622years, 500000 would have disintegrated. These phenomenon can never be experienced by stable isotopes as such they can not be used in carbon dating techniques. reason why uranium-238 is mostly and commonly used in the earth crust to estimate the ages of rocks because it has a half life of 4.5 x 10^9 years.
And also, the radioactive isotopes of most common light element are short, they have very short half life (few days or weeks) and they decay rapidly to vanshing point, as such, they are not found in nature to any reasonable extent.
Answer:
44 grams of CO₂ will be formed.
Explanation:
The balanced reaction is:
C + O₂ → CO₂
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:
- C: 1 mole
- O₂: 1 mole
- CO₂: 1 mole
Being the molar mass of each compound:
- C: 12 g/mole
- O₂: 32 g/mole
- CO₂: 44 g/mole
By stoichiometry the following mass quantities participate in the reaction:
- C: 1 mole* 12 g/mole= 12 g
- O₂: 1 mole* 32 g/mole= 32 g
- CO₂: 1 mole* 44 g/mole= 44 g
The limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.
If 12 grams of C react, by stoichiometry 32 grams of O₂ react. But you have 40 grams of O₂. Since more mass of O₂ is available than is necessary to react with 12 grams of C, carbon C is the limiting reagent.
Then by stoichiometry of the reaction, you can see that 12 grams of C form 44 grams of CO₂.
<u><em>44 grams of CO₂ will be formed.</em></u>
Classify what. explain more
Mole fraction for silver= 0.2317643/0.3079193
= 0.7526787
Mole fraction for gold=0.076155/0.3079193
=0.2473212
What is Molar Fraction?
The mole fraction is the product of the number of molecules of a specific component in a mixture and its total molecular weight. It serves as a means of indicating how concentrated a solution is.
It is a unit of concentration, defined as the product of the moles of a component and the moles of the entire solution. When all the parts of a solution are summed up, their mole fraction equals 1.
molar mass of silver = 107.8682g/mol
Molar mass of gold= 196.96657g/mol
Therefore mole = mass/molar mass
For silver: 25g/107.8682g/mol = 0.2317643mol
For gold: 15g/196.96657g/mol= 0.076155mol
Total number of mole= 0.2317643+0.076155
= 0.30791193mol
Mole fraction for silver= 0.2317643/0.3079193
= 0.7526787
Mole fraction for gold=0.076155/0.3079193
=0.2473212
Learn more about Mole Fraction from given link
brainly.com/question/28590918
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