Problem One
You will use both m * c * deltaT and H = m * heat of fusion.
Givens
m = 12.4 grams
c = 0.1291
t1 = 26oC
t2 = 1204
heat of fusion (H_f) = 63.5 J/grams.
Equation
H = m * c * deltaT + m * H_f
Solution
H = 12.4 * 0.1291 * (1063 - 26) + 12.4 * 63.5
H = 1660.1 + 787.4
H = 2447.5 or 2447.47 is the exact answer. I have to leave the rounding to you. I have no idea where to round it although I suspect 2450 would be right for 3 sig digs.
Problem Two
Formula and Givens
t1 = 14.5
t2 = 50.0
E = 5680
c = 4.186
m = ??
E = m c * deltaT
Solution
5680 = m * 4.186 * (50 - 14.5)
5680 = m * 4.186 * (35.5)
5680 = m * 148.603 * m
m = 5680 / 148.603
m = 38.22 grams That isn't very much. Be very sure you are working in joules. You'd leave that many grams in the kettle after drying it thoroughly.
m = 38.2 to 3 sig digs.
Answer:
<u><em>The correct answer is:</em></u>
<h3><u><em>
Option D: Evapotranspiration </em></u></h3>
<u><em>Water is removed both from the plants and the soil. Evapotranspiration is a process by which the water is removed from plants and ground and is added back into the atmosphere. From ground, water is removed in the form of evaporation from the soil. And from plants the water is removed by transpiration. Hence the term Evapotranspiration.</em></u>
Answer:
Kr-81 is most stable because of its high half lige and kr-73 is the most radioactive because of its least half life
Explanation:
Stability is directly proportional to half life of a reaction