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I am Lyosha [343]
3 years ago
7

Krypton-79 has a half-life of 35 hours. how many half-lives have passed after 105 hours?

Chemistry
1 answer:
Nookie1986 [14]3 years ago
6 0
The number of half -lives that has passed after 105  hours  for krypton-79 that has  half-life of 35 hours is calculated as below

if 1 half life = 35 hours

what about 105 hours = ? half-lives

= (1 half life  x105  hours) /35 hours = 3 half-lives  has passed after 105 hours
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Answer:

470 °C  

Explanation:

This looks like a case where we can use Charles’ Law:  

\dfrac{V_{1}}{T_{1}} =\dfrac{V_{2}}{T_{2}}

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\begin{array}{rcl}\dfrac{V_{1}}{T_{1}}& =&\dfrac{V_{2}}{T_{2}}\\\\ \dfrac{\text{20 L}}{\text{373.15 K}} &=&\dfrac{\text{40 L}}{T_{2}}\\\\{\text{15 000 K}} & = & 20T_{2}\\T_{2} & = &\dfrac{\text{15 000 K}}{20 }\\\\T_{2} & = & \textbf{750 K}\\\end{array}

Note: The answer can have only two significant figures because that is all you gave for the volumes.

(c) Convert the temperature to Celsius

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The internal energy of a system is always increased by ________. A. adding heat to the system B. adding heat to the system and h
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PubChem CID 6393

Structure  

Find Similar Structures

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Answer is: it takes 116,8 seconds to fall to one-sixteenth of its initial value

<span> The half-life for the chemical reaction is 29,2 s and is independent of initial concentration.
c</span>₀ - initial concentration the reactant.

c - concentration of the reactant remaining at time.

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