Answer:
Ice melts into liquid water- endothermic
A process with a calculated positive q - endothermic
Wood burns in a fireplace - exothermic
A process with a calculated negative q - exothermic
Acid and base are mixed, making test tube feel hot - exothermic
Solid dissolves into solution, making ice pack feel cold - endothermic
Explanation:
An endothermic process is one in which heat is absorbed from the surroundings. The absorption of heat means that heat is removed from the surroundings hence the surroundings feel cool. When heat is absorbed, q is positive.
An exothermic process is one in which heat is released to the surroundings. The evolution of heat means that heat is released into the surroundings hence the surroundings feel hot . When heat is evolved, q is negative.
Answer:
A. Sometimes the coefficient for the oxygen molecule is not a whole number
Explanation:
B. Scientific claims can be verified through observation and experimentation, while pseudoscientific claims cannot. At least I think it is right.
It will take 1.11 min to heat the sample to its melting point.
Melting point = - 20°C
Boiling point = 85°C
∆H of fusion = 180 J/g
∆H of vap = 500 J/g
C(solid) = 1.0 J/g °C
C(liquid) = 2.5 J/g °C
C(gas) = 0.5 J/g °C
Mass of sample = 25 g
Initial temperature = - 40°C
Final temperature = 100°C
Rate of heating = 450 J/min
Specific heat capacity formula:- q = m ×C×∆T
Here, q = heat energy
m = mass
C = specific heat
∆T = temperature change
Melting point = - 20°C
C(solid) = 1.0 J/g °C
∆T = final temperature - initial temperature = -20 - (-40) = 20
Put these value in Specific heat capacity formula
q = m ×C×∆T
q = 25×1.0×20
=500J
The Rate of heating = 450 J/min
i.e. 450J = 1min
so, 500J = 1.11min
1.11 minutes does it take to heat the sample to its melting point.
The specific heat capacity is defined as the amount of heat absorbed in line with unit mass of the material whilst its temperature increases 1 °C.
Learn more about specific heat capacity here:- brainly.com/question/26866234
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Answer:
The answer to your question is: V2 = 1.94 l
Explanation:
Data
V1 = 2.42 l
T1 = 25°C
P1 = 1 atm
V2 = ?
T2 = 25 -11 = 14°C
P2 = 1(0.7) = 0.7 atm
Formula
P1V1/T1 = P2V2/T2
Clear V2 from the equation
V2 = P1V1T2/ P2T1
V2 = (1)((2.42)(14) / (0.7)(25)
V2 = 33.88 / 17.5
V2 = 1.94 l
