☃️ Chemical formulae ➝
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<u>How to find?</u></h3>
For solving this question, We need to know how to find moles of solution or any substance if a certain weight is given.
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<u>Solution:</u></h3>
Atomic weight of elements:
Ca = 40
C = 12
O = 16
❍ Molecular weight of
= 40 + 12 + 3 × 16
= 52 + 48
= 100 g/mol
❍ Given weight: 10 g
Then, no. of moles,
⇛ No. of moles = 10 g / 100 g mol‐¹
⇛ No. of moles = 0.1 moles
☄ No. of moles of Calcium carbonate in that substance = <u>0.1 moles</u>
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The atomic number is equal to the number of protons
Answer:
k = 6.31 x 10⁻³ min⁻¹
Explanation:
The equation required to solve this question is:
k = 0693 / t half-life
This equation is derived from the the equation from the radioctive first order reactions:
ln At/A₀ = -kt
where At is the number of isoopes after a time t , and A₀ is the number of of isotopes initially. The half-life is when the number of isotopes has decayed by a half, so
ln(1/2) = -kt half-life
-0.693 = - k t half-life
t half-life = 109.8 min
⇒ k = 0.693 / t half-life = 0.693 / 109.8 min = 6.31 x 10⁻³ min⁻¹