Answer:
After 90 minutes 5.15625 g amount left from total of 165 g.
Explanation:
Given data:
Technetium-104 half life = 18.0 min
Total amount of sample = 165 g
Amount left after 90.0 min = ?
Solution:
First of all we will calculate the number of half lives passes.
Number of half lives = T elapsed / Half life
Number of half lives = 90 min /18.0 min
Number of half lives = 5
Amount left:
At time 0 = 165 g
At first half life = 165 g/ 2= 82.5 g
At 2nd half life = 82.5 g/2 = 41.2 g
At 3rd half life = 41.2 g/ 2 = 20.625 g
At 4th half life = 20.625 g/ 2 = 10.3125 g
At 5th half life = 10.3125 g /2 = 5.15625 g
Thus, after 90 minutes 5.15625 g amount left from total of 165 g.
Below are the choices:
a)0.2168 atm
<span>b)4.613 atm </span>
<span>c)34.60 atm </span>
<span>d467.4 atm
</span>
1 atm = 760mmHg : Therefore:
<span>3,506mmHg = 3,506/760 = 4.613 atm
</span>B is correct answer.
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Answer:
K₃PO₄ + 3HCl ⇒ 3KCl + H₃PO₄
Explanation:
practice these, it gets easier. goal is to match the amount of reactants and products on both sides of the equation. cheers!