As a transverse wave travels through a medium it displaces the particles

1. 412.9 g of dry ice sublimes at room temperature. a. What’s changing? --- sublimation b. What constant will you use? ----- 25.

hoa [83]

1. 236 kJ

a. The phase (or state of matter) of the substance: from solid state to gas state (sublimation)

b. The enthalphy of sublimation, given by: $\lambda=571 J/g$

c. The equation to use will be $Q=m\lambda$ , where m is the mass of dry ice and $\lambda$ is the enthalpy of sublimation

d. The energy is being absorbed, because the heat is transferred from the environment to the dry ice: as a consequence, the bonds between the molecules of dry ice break and then move faster and faster, and so the substance turns from solid into gas directly.

e. The amount of energy being transferred is

$Q=m\lambda=(412.9 g)(571 J/g)=2.36\cdot 10^5 J=236 kJ$

2. 165 kJ

a. The phase (or state of matter) of the substance: from gas state to liquid state (condensation)

b. The latent heat of vaporisation of water, given by $\lambda=2260 J/g$

c. The equation to use will be $Q=m\lambda$ , where m is the mass of steam that condenses and $\lambda$ is the latent heat of vaporisation

d. The energy is being released, since the substance turns from a gas state (where molecules move faster) into liquid state (where molecules move slower), so the internal energy of the substance has decreased, therefore heat has been released

e. The amount of energy being transferred is

$Q=m\lambda=(72.9 g)(2260 J/g)=1.65\cdot 10^5 J=165 kJ$

3. 3.64 kJ

a. Only the temperature of the substance (which is increasing)

b. The specific heat capacity of silver, which is $C_s = 0.240 J/gC$

c. The equation to use will be $Q=m C_s \Delta T$ , where m is the mass of silver, Cs is the specific heat capacity and $\Delta T$ the increase in temperature

d. The energy is being absorbed by the silver, since its temperature increases, this means that its molecules move faster so energy should be provided to the silver by the surroundings

e. The amount of energy being transferred is

$Q=m C_s \Delta T=(39.2 g)(0.240 J/gC)(412.9^{\circ}C-25.9^{\circ}C)=3641=3.64 kJ$

4. 89 kJ

a. Both the phase of the substance (from solid to liquid) and then the temperature

b. The latent heat of fusion of ice: $\lambda=334 J/g$ and the specific heat capacity of water: $C_s=4.186 J/gC$

c. The equation to use will be $Q=m\lambda + m C_s \Delta T$ , where m is the mass of ice, $\lambda$ the latent heat of fusion of ice, Cs is the specific heat capacity of water and $\Delta T$ the increase in temperature

d. The energy is being absorbed by the ice, at first to break the bonds between the molecules of ice and to cause the melting of ice, and then to increase the temperature of the water

e. The amount of energy being transferred is

$Q=m\lambda +m C_s \Delta T=(156.3 g)(334 J/g)+(156.3 g)(4.186 J/gC)(56.232^{\circ}C-0^{\circ}C)=8.9\cdot 10^4 J=89 kJ$

6 0

3 years ago

What will happen if you didn’t have chemical energy in your body

Maru [420]

Absence of chemical energy in the body, can and will eventually lead to death.

3 0

3 years ago

How will the electrostatic force be changed if the distance between electric charges is reduced one half of the original distanc

GuDViN [60]

I think the answer to your question is A

8 0

3 years ago

Your friend says that the law of momentum conservation is violated when a ball rolls down a hill and gains momentum. What do you

pochemuha

Answer:

The friend is wrong: the law of conservation of momentum is not violated

Explanation:

The law of conservation of momentum states that:

"For a system of an object, if the net external force acting on the system is zero, then the total momentum of the system is conserved"

In our problem, the system is the ball rolling down the hill. The ball gains speed as it rolls down, so its momentum increases, according to the equation:

$p=mv$

where m is the mass of the ball and v its velocity. This may appear as a violation of the law, however it is not. In fact, the net external force acting on the ball is not zero, since there is the force of gravity acting on the ball. As a result, the force of gravity gives an acceleration to the ball, increasing its momentum: therefore, the law is not violated.

8 0

3 years ago

Which of the following scientists did not contribute significant discoveries to physical science.

vfiekz [6]

the answer is C.....

8 0

3 years ago