A well designed experiment can be replicated by other true or false

4). One mole of monoclinic sulfur at 25C was placed in a constant-pressure calorimeter whose heat capacity (C) was 1620 J/K. T

andre [41]

Answer: The enthalpy change of the reaction is -243 J/mol

Explanation:

The heat released by the reaction is absorbed by the calorimeter and the solution.

The chemical equation used to calculate the heat released follows:

$q=c\times \Delta T$

where,

c = heat capacity of calorimeter = 1620 J/K

$\Delta T$ = change in temperature = $0.150^oC=0.150K$ (Change remains same)

Putting values in above equation, we get:

$q=1620J/K\times 0.15K=243J$

Sign convention of heat:

When heat is absorbed, the sign of heat is taken to be positive and when heat is released, the sign of heat is taken to be negative.

For the given chemical reaction:

$S\text{ (monoclinic)}\rightarrow S\text{ (orthorhombic)}$

We are given:

Moles of monoclinic sulfur = 1 mole

To calculate the enthalpy change of the reaction, we use the equation:

$\Delta H_{rxn}=\frac{q}{n}$

where,

q = amount of heat released = -243 J

n = number of moles = 1 mole

$\Delta H_{rxn}$ = enthalpy change of the reaction

Putting values in above equation, we get:

$\Delta H_{rxn}=\frac{-243J}{1mol}=-243J/mol$

Hence, the enthalpy change of the reaction is -243 J/mol

8 0

3 years ago

How could you ensure that all the spectroscopes used the same calibration line and equation? What would you need to be sure was

NISA [10]

People had asked this many times and that is why they came up with methods and standards that will answer these type of questions. You can look it up in the NIST or the National Institute for Standards and Technology.

8 0

2 years ago

What happens to the water molecules when water at 24°C is cooled to 0°C

Softa [21]

Well if it were to freeze , the molecules move and become a solid slowly

5 0

2 years ago

Chris the chemist was working in the and he wanted to sou what would happen he put copper chloride into a Bunsen flameAs soon as

Reptile [31]

The question is incomplete, the complete question is;

Chris the Chemist was working in the lab, and he wanted to see what would happen if he put copper chloride into a Bunsen burner flame. As soon as he put it in the flame, it began to emit a green color. Which of these BEST describes this outcome?

A) The heat split the nucleus and created a new element.

B) As the copper chloride was heated, electrons were turned into neutrons.

C) As the electrons moved to a higher energy level, a photon of light is emitted.

D) When excited electrons return back to the ground state, a photon of light is emitted.

Answer:

D) When excited electrons return back to the ground state, a photon of light is emitted.

Explanation:

According to Bohr's model of the atom, electrons may absorb energy and move up to higher energy levels.

These electrons quickly return to ground state from such higher energy excited states thereby emitting the excess energy absorbed during excitation.

If the higher energy level is E2 and the ground state is E1 then the energy of the photon emitted when the electron descends from energy level E2 to E1 is;

ΔE = E2 - E1

This photon emitted accounts for the green colour of the copper salt observed when it was heated.

4 0

3 years ago

Explain how the processes that occur at mid-ocean ridges and ocean trenches illustrate the cycling of matter.

Nimfa-mama [501]

Explanation:

At one end, new crusts are being produced, at other end the crust is being destroyed and this strikes a unique balance.

At the mid-ocean ridges, the lithospheric plates are diverging. This is implies that the earth is pulling apart here. When the earth is pulling apart, new materials from the asthenosphere comes to the surface thereby creating new lithospheric plate.

As new plates are formed, they push back against the old one. New plates are found very close to the margin and it begins to age away from the margin.

On the other end, old plates are taken away from this center to ocean trenches. At oceanic trenches subduction is occurring.

In a subduction, the lithospheric plate plunges deep into the asthenosphere where they are being melted back.

This is a covergent margin.

This process continues in a dynamic manner to cycle matter on earth.

learn more:

Sea floor spreading brainly.com/question/9912731

#learnwithBrainly

3 0

2 years ago