Answer: This is called moles
Explanation: This is described to be the number of molecules, atoms or ions in a substance :)
Given :
Initial mass , a = 150 gm .
Half time ,
.
Final mass , x = 18.75 gm .
To Find :
The time taken to decay 18.75 gm .
Solution :
We know , time taken is given by :
Here , k is a constant given by :
Putting all given value in above equation :
We get :
Therefore , time taken is 6.94 hours .
Hence , this is the required solution .
The answer is
14.14 x 10^-2
Answer:
83ºC
Explanation:
A bomb calorimeter is an instrument used to measure the heat that release or absorb a particular reaction.
The reaction of combustion of propane is:
C₃H₈ + 5O₂ → 3 CO₂ + 4 H₂O ΔH = -2222kJ/mol
<em>1 mole of propane release 2222kJ</em>
10.0g of propane (Molar mass: 44.1g/mol).
10.0g ₓ (1mol/ 44.1g) = <em>0.227 moles of C₃H₈</em>
If 1 mole of propane release 2222kJ, 0.227moles will release (Release because molar heat is < 0):
0.227 moles of C₃H₈ ₓ (2222kJ / mol) = 504kJ.
Our calorimeter has a constant of 8.0kJ/ºC, that means if there are released 8.0kJ, the bomb calorimeter will increase its temperature in 1ºC. As there are released 504kJ:
504kJ ₓ (1ºC / 8.0kJ) = 63ºC will increase the temperature in the bomb calorimeter.
As initial temperature was 20ºC, final temperature will be:
<h2>83ºC</h2>
Density = Mass/Volume
d = .254/129.4
