Chemistry, 07.04.2020 19:26 gameranonymous266

Compounds like CCl2F2 are known as chlorofluorocarbons, or CFCs. These compounds were once widely used as refrigerants but are now being replaced by compounds that are believed to be less harmful to the environment. The heat of vaporization of CCl2F2 is 289 J/g.

What mass (in grams) of this substance must evaporate to freeze 200g of water initially at 15 degrees C?

(The heat of fusion of water is 334 J/g; the specific heat of water is 4.18 J/g-K.)

Answers: 2

Show answers

Answers

Answer from: mrsrobinson1014

1. Given Data:

The heat of vaporization of CCl2F2 is 289 J/g. Mass of water (H2O) = 200 grams Temperature of water = 15.0 °C = 15 - 273 = 288 K The freezing temperature = 0°C = 273 K The heat of fusion of water is 334 J/g The specific heat of water is 4.18 J/g*K

2.The heat release to cool the water from (15.0 °C → 0°C):

Q = m*c*ΔT Q = 200 * 4.18 * (15) Q = 12540 J

3.The energy needed to freeze the water:

Q = m*ΔHfus Q = 200 grams * 334J/g Q = 66800 J

4.The total heat released

Q= Heat release+Energy needed to be freezeQ = 12540 + 66800 Q = 79340 J

5.The mass of this substance must evaporate

The total heat released = 79340 J

CCl2F2 = 289 J/g.

Q = m*ΔH(vaporization)79340 J = m * 289 J/g m = 79340 J /289 J/g m = 274.5 grams

274.5 grams of this substance must evaporate to freeze 200 grams of water of 15 °C.

Learn more :

link

Answer from: Sushmitarai9416

274.5 grams of this substance must evaporate to freeze 200 grams of waterof 15 °C

Explanation:

Step 1: data given

The heat of vaporization of CCl2F2 is 289 J/g.

Mass of water (H2O) = 200 grams

Temperature of water = 15.0 °C = 15 - 273 = 288 K

The final temperature of water = the freezing temperature = 0°C = 273 K

The heat of fusion of water is 334 J/g

the specific heat of water is 4.18 J/g*K

Step 2: Calculate the heat release to cool the water from (15.0 °C → 0°C)

Q = m*c*ΔT

⇒with Q = the heat released = TO BE DETERMINED

⇒with m = the mass of water = 200 grams

⇒with c = the specific heat of water is 4.18 J/g*K

⇒with ΔT = the change of temperature of water = 15 °C

Q = 200 * 4.18 * (15)

Q = 12540 J

Step 3: Calculate the energy needed to freeze the water

Q = m*ΔHfus

Q = 200 grams * 334J/g

Q = 66800 J

Step 4: Calculate the total heat released

Q = 12540 + 66800

Q = 79340 J

Step 5: Calculate the mass of this substance must evaporate

Q = m*ΔH(vaporization)

⇒with Q = the total heat released = 79340 J

⇒with m = the mass of CCl2F2 = TO BE DETERMINED

⇒with ΔH(vaporization) = the heat of vaporization of CCl2F2 = 289 J/g.

79340 J = m * 289 J/g

m = 79340 J /289 J/g

m = 274.5 grams

274.5 grams of this substance must evaporate to freeze 200 grams of waterof 15 °C

Answer from: Quest

7is b8 is d9 is c10 is a11 is d

Answer from: Quest

Cause its being chemically applied?

Another question on Chemistry

Chemistry, 22.06.2019 12:30

Which of the following describes a compound? (hint: carbon and oxygen bo a. a piece of pure carbon, containing only carbon atoms b. oxygen gas surrounding a solid piece of carbon c. a substance made of two oxygen atoms for each carbon atom carbon and oxygen atoms mixed without being bonded together

Answers: 1

Answer

Chemistry, 22.06.2019 20:30

We are hoping to create 5.72 grams of glucose. the plant was given 4.75 liters of co2 and 2.81 g of h20. which reactant was the limiting reagent? how much excess mass did we have of the other reactant?

Answers: 3

Answer

Chemistry, 22.06.2019 21:00

In the experiment you asked to react hydrochloric acid and with sodium hydroxide. when measuring the volume of the reactants, which instrument would give the greatest precision.

Answers: 3

Answer

Chemistry, 22.06.2019 21:30

How many oxygen atoms are there in 3.15 moles of hcl manganese (iv) oxide, mno2

Answers: 2

Answer

You know the right answer?

Compounds like CCl2F2 are known as chlorofluorocarbons, or CFCs. These compounds were once widely us...

Questions

Chemistry, 19.12.2019 21:31

Two sample of carbon tetrachloride are decomposed into their constituent elements. one sample produces 32.4 g of carbon and 373 g of chlorine, and the...