The initial temperature is 137.34 °C.
<u>Explanation:</u>
As the specific heat formula says that the heat energy required is directly proportional to the mass and change in temperature of the system.
Q = mcΔT
So, here the mass m is given as 23 kg, the specific heat of steel is given as c = 490 J/kg°C and the initial temperature is required to find with the final temperature being 140 °C. Also the heat energy required is 30,000 J.
ΔT =
ΔT =
Since the difference in temperature is 2.66, then the initial temperature will be
Final temperature - Initial temperature = Change in temperature
140-Initial temperature = 2.66
Initial temperature = 140-2.66 = 137.34 °C
Thus, the initial temperature is 137.34 °C.
Answer:
Approx. 4⋅g.
Explanation:
Moles of sulfuric acid =10.0⋅g98.08⋅g⋅mol−1=0.102⋅mol.
Now we have the molar quantity of sulfuric acid that react; we also have the stoichiometric equation that shows the molar equivalence of sulfuric acid, and lithium hydroxide.
Given the stoichiometry,
mass of water =0.102⋅mol×2×18.01.g.mol−1=??⋅g.
Why did I multiply the mass in this equation by 2? Am I pulling your leg?
Colligative
properties calculations are used for this type of problem. Calculations are as
follows:<span>
</span>
<span>ΔT(freezing point)
= (Kf)m
ΔT(freezing point)
= 1.86 °C kg / mol (0.705)
ΔT(freezing point) = 1.3113 °C
</span>
<span>
</span>
<span>Hope this answers the question. Have a nice day.</span>