The question is incomplete, the complete question is;
An alcohol thermometer makes use of alcohol's changing _______ in order to measure temperature. As the temperature goes up, the alcohol contained in the thermometer increases in volume, filling more of the thermometer's tube.
A.
mass
B.
state
C.
chemical composition
D.
density
Answer:
D.
density
Explanation:
Every kind of thermometer makes use of a change in a particular physical property of a substance as a measure of temperature. It must be a property that changes with temperature.
Density of a substance changes with temperature. Even though the mass of alcohol in glass remains constant, but its volume increases or decreases with change in temperature leading to a change in volume and consequently a change in density of the alcohol in glass. This change is used as a measure of the change in temperature.
Answer:
The volume of the Kleenex box is 64 cm.
Explanation:
Volume = B x W x H
So: V = 8cm x 2cm x 4cm = 64cm
Answer:
ΔS = -661.0J/mol is the entropy change for the system
ΔS = -842J/mol.K is the entropy change for the surroundings
Explanation:
From the relationship between ΔG, T, ΔH and ΔS,
Mathematically, ΔG = ΔH - TΔS
TΔS = ΔH - ΔS
ΔS = ΔH - ΔS / T
but ΔG = -54 kJ/mol, ΔH = -251 kJ/mol and T = 25 °C (298 K)
plugging into the equation,
ΔS = -251 kJ/mol - ( -54 kJ/mol) / 298
ΔS = -0.6610KJ/mol or in J.mol
ΔS = -661.0J/mol is the entropy change for the system
- For entropy change for the surroundings = ΔS = ΔH/T
- ΔS = -0.84KJ/mol.K or -842J/mol.K is the entropy change for the surroundings
Pure substances are substances which are homogenous in nature. They either consists of atoms of 1 kind or molecules of 1 kind. Atoms are seen in elements, where as molecules are seen in compounds like Acids, Bases, etc.
They mostly have fixed properties like boiling and melting points and are uniform in nature. :D
