Considering the definition of calorimetry and sensible heat, the change in temperature if the gold releases 0.106 kJ of heat as it cools is 28.78°C.
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
Sensible heat is the amount of heat that a body absorbs or releases without any changes in its physical state (phase change). It is calculated by the expression:
Q = c× m× ΔT
where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.
In this case, you know:
- Q= 0.106 kJ= 106 J (being 1 kJ=1000 J)
- c= 25.4
- m= 28.5 g×
= 0.145 moles (being 196.967 g/mole the molar mass of gold) - ΔT= ?
Replacing:
106 J= 25.4 × 0.145 moles× ΔT
Solving:
ΔT=
ΔT= 28.78 C
The change in temperature if the gold releases 0.106 kJ of heat as it cools is 28.78°C.
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Explanation:
During this time, unusual winds cause warm surface water from the equator to move east, toward Central and South America. El Niño can
Answer:
0.02 m
Explanation:
∆U = q + w
w = ∆U - q = (1380 - 2040) J = -660 J
w = -p∆V = -pA∆h
∆h = -w/(pA)
p = 1 bar × (100000 Pa/1 bar) = 100000 Pa
∆h = -(-660 J)/(100000 Pa×0.33 m²) = 0.02 m
Answer: (A) 
(B) 
Explanation:
(A) As we know that HCl is a strong acid and when it is added to an aqueous solution then it leads to increase in the concentration of hydrogen ions. And, when an acid or base is added to a solution then any resistance by the solution in changing the pH of the solution is known as a buffer.
This means that addition of buffer into the given solution will not cause much change in the concentration of 
in large amount.
As both the buffer components are salt then they will remain dissociated as follows.
Hence, net ionic equation will be as follows.
(B) When we add small amount of sodium hydroxide into the solution then there will occur an increase in concentration of hydroxide ions into the solution. But then due to the presence of buffer there will occur not much change in concentration and the acid will get converted into salt.
The net ionic equation is as follows.
Answer:
True.
Explanation:
Iodine is an essential element required for the synthesis of Thyroxine is a correct statement.
Iodine is an essential and controlling medium for thyroid hormone production, as a minor ingredient. It is an important element in the development of thyroid hormones thyroxine (T4) and triiodothyronine (T3) by the thyroid gland.
