The first step to answering this item is to convert the given temperatures in °F to °C through the equation,
°C = (°F - 32)(5/9)
initial temperature: 72°F
°C = (72 - 32)(5/9) = 22.22°C
final temperature: 145°F
°C = (145 - 32)(5/9) = 62.78°C
Substituting to the equation,
H = mcpdT
H = (43 g)(0.903 J/g°C)(62.78 - 22.22)
H = 1574.82 J
<em>Answer: 1574.82 J</em>
The idea is that all continents move at a rate of approximately 2 inches per year because their moving ever since pangea (all continents were one) separated
<u>Answer:</u> The atomic weight of the second isotope is 64.81 amu.
<u>Explanation:</u>
Average atomic mass of an element is defined as the sum of atomic masses of each isotope each multiplied by their natural fractional abundance
Formula used to calculate average atomic mass follows:
.....(1)
We are given:
Let the mass of isotope 2 be 'x'
Mass of isotope 1 = 62.9 amu
Percentage abundance of isotope 1 = 69.1 %
Fractional abundance of isotope 1 = 0.691
Mass of isotope 2 = 'x'
Percentage abundance of isotope 2 = 30.9%
Fractional abundance of isotope 2 = 0.309
Average atomic mass of copper = 63.5 amu
Putting values in equation 1, we get:
![\text{Average atomic mass of copper}=[(62.9\times 0.691)+(x\times 0.309)]](https://tex.z-dn.net/?f=%5Ctext%7BAverage%20atomic%20mass%20of%20copper%7D%3D%5B%2862.9%5Ctimes%200.691%29%2B%28x%5Ctimes%200.309%29%5D)

Hence, the atomic weight of second isotope will be 64.81 amu.
Phenolphthalein is an indicator used in chemistry to detect acidic or basic/alkaline solutions.It is often used in the lab as an indicator used to carry out accurate titration using soluble reactants.