An unknown substance has a mass of 0.125 kg and an initial temperature of 90.5°c. the substance is then dropped into a calorimeter made of aluminum containing 0.285 kg of water initially at 29.5°c. the mass of the aluminum container is 0.150 kg, and the temperature of the calorimeter increases to a final equilibrium temperature of 32.0°c. assuming no thermal energy is transferred to the environment, calculate the specific heat of the unknown substance.

The specific heat capacity of the substance = 455.38 J/kgK

Explanation:

Heat lost by the substance = Heat gained by water + heat gained by the aluminum calorimeter

Qs = Qw + Qc equation 1

Where Qs = heat lost by the substance, Qw = heat gain by water, Qc = heat gain by the aluminum calorimeter.

Qs = c₁m₁(T₁-T₃) equation 2

Qw = c₂m₂(T₃-T₂) equation 3

Qc = c₃m₃(T₃-T₂) equation 4

Where c₁ = specific heat capacity of the substance, m₁ = mass of the substance, c₂ = specific  heat capacity of water, m₂ = mass of water, c₃ = specific heat capacity of aluminium, m₃ = mass of the aluminum container, T₁ = Initial Temperature of the substance, T₂ = initial temperature of water, T₃ = Final equilibrium temperature.

Substituting equation 2, 3, 4 into equation 1

c₁m₁(T₁-T₃) = c₂m₂(T₃-T₂) + c₃m₃(T₃-T₂) equation 5

Making c₁ the subject of equation 5

c₁ =  {c₂m₂(T₃-T₂) + c₃m₃(T₃-T₂)}/m₁(T₁-T₃) equation 6

Where c₂ = 4200 J/kgK, m₂ = 0.285 kg, m₁ = 0.125 kg, c₃ = 900 J/kgK, m₃= 0.150 kg, T₁ = 90.5°C, T₂ = 29.5°C, T₃ =  32.0°C

Substituting these values into Equation 6,

c₁ = {4200×0.285(32-29.5) + 900×0.150(32-29.5)}/0.125(90.5-32)

c₁ = {1197(2.5) + 135(2.5)}/7.3125

c₁ = {2992.5 + 337.5}/7.3125

c₁ = 3330/7.3125

c₁ = 455.38 J/kgK.

Therefore the specific heat capacity of the substance = 455.38 J/kgK

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.