<span>6 + x = 12. To evaluate an algebraic expression, you have to substitute a number for each variable and perform the arithmetic operations. In the example above, the variable x is equal to 6 since 6 + 6 = 12. If we know the value of our variables, we can replace the variables with their values and then evaluate the expression.</span>
Answer: Option (c) is the correct answer.
Explanation:
Entropy is defined as the degree of randomness. This means that more is the number of collisions taking place between atoms of a substance more will be the randomness.
Therefore, more will be the entropy of substance. We cannot measure the entropy but we can measure the change in entropy of a substance.
A thermometer is a glass tube that contains a liquid column generally mercury, and it is usually used to measure the temperature of human body.
A calorimeter is a device or apparatus that is used in a chemical reaction to measure the amount of heat involved.
Therefore, we can conclude that the student can't measure entropy directly, only an entropy change.
Answer:
S(metal) = 0.66J/g°C
Explanation:
We can find specific heat of a material, S, using the equation:
q = m*S*ΔT
<em>Where q is change in heat, m is the mass of the substance, S specific heat and ΔT change in temperature.</em>
The heat given by the metal is equal to the heat that water absorbs, that is:
m(Metal)*S(metal)*ΔT(Metal) = m(Water)*S(water)*ΔT(water)
<em>Where:</em>
m(Metal) = 76.0g
S(metal) = ?
ΔT(Metal) = 96.0°C-31.0°C = 65.0°C
m(Water) = 120.0g
S(water) = 4.184J/g°C
ΔT(water) = 31.0°C-24.5°C = 6.5°C
Replacing:
76.0g*S(metal)*65.0°C = 120.0g*4.184J/g°C*6.5°C
S(metal) = 0.66J/g°C
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The law of conservation applies because the energy is not been created or destroyed. The energy that the metal gives is absorbed by the water.
