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3 years ago

Help plz:)))I’ll mark u Brainliest

Chemistry

1 answer:

Triss [41]3 years ago

6 0

Answer:

Explanation:

We want the energy required for the transition:

CO 2 ( s ) + Δ → C O 2 ( g )

Explanation:

We assume that the temperature of the gas and the solid are EQUAL.

And thus we simply have to work out the product:

2 × 10^ 3 ⋅ g × 196.3 ⋅ J ⋅ g − 1 to get an answer in Joules as required.

What would be the energy change for the reverse transition:

C O 2 ( g ) + → C O 2 ( s ) ?

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Compounds like CCl₂F₂ are known as chlorofluorocarbons, or CFCs. These compounds were once widely used as refrigerants but are n

Nataliya [291]

Explanation:

The given data is as follows.

Specific heat of water = $4.18 J/g^{o}C$

Heat of fusion of water = 334 J/g

Mass of water = 200 g

On bringing water at $0^{o}C$ , heat released will be as follows.

$q_{1} = m \times C \times \Delta T$

= $200 g \times 4.18 J/g^{o}C \times (0 - 15)^{o}C$

= -12540 J

or, = -12.540 kJ (as 1 kJ = 1000 J)

Now, calculate the heat releasedwhen water freezes at $0^{o}C$ as follows.

$q_{2} = mass \times \text{-heat of fusion}$

= $200 g \times -334 J/g$

= -66800 J

or, = -66.80 kJ

Therefore, total heat released in freezing water will be as follows.

$q_{total} = q_{1} + q_{2}$

= (-12.540 - 66.80) kJ

= -79.34 kJ

Hence,

amount of heat released in freezing water = heat used to vaporize $CCl_{2}F_{2}$

Now, heat of vaporization of $CCl_{2}F_{2}$ = 289 J/g

Total heat released in freezing water = -79.34 kJ

Heat consumed to vaporize $CCl_{2}F_{2}$ = 79.34 kJ = -79340 J

Therefore, calculate the mass of $CCl_{2}F_{2}$ vaporized as follows.

Mass of $CCl_{2}F_{2}$ vaporized = $\frac{\text{heat consumed}}{\text{heat of vaporization}}$

= $\frac{79340 J}{289 J/g}$

= 274.53 g

Thus, we can conclude that 274.53 g mass of this substance must evaporate to freeze 200 g of water initially at $15^{o}C$ .

5 0

4 years ago

Hat is the molar mass of a substance?

Morgarella [4.7K]

The molar mass is what would you find on the periodic table and it is used in the mole conversions within chemistry. So the answer would have to be A: the mass in grams of one mole of a substance.

7 0

3 years ago

The physical state of CaBr2 at room temperature? Predict the two other properties of CaBr2 Deduce the charge of ion Ca in the co

Fofino [41]

Answer:

CaBr2 is a colorless solid and the charge on Calcium is +2

Explanation:

CaBr2 is a colorless solid at room temperature.

Other properties include -

a) It is a crystalline solid

b) Melting point of 765°C.

c) It is deliquescent

d) Soluble in water and absolute alcohol.

The charge of Br is -1. Here two atoms of Br attaches with one atom of calcium. Hence the charge of calcium is +2

7 0

3 years ago

Which of the following would help you identify a titration curve that involved a strong acid titrated by a weak base?

Mariulka [41]

Answer:

The pH at the equivalence point is lower than 7

Explanation:

Given the titration involves a strong acid and a weak base

An example is the reaction between ammonia and hydrochloric acid in the aqueous phase

The pH of the base will ordinarily start high and drop rapidly with the additions of acid. As the equivalence point is approached, the pH will change more gradually, until finally one drop will cause a rapid pH transition through the equivalence point.

If a chemical indicator is used—methyl orange would be a good choice in this case—it changes from its basic to its acidic colour.

In strong acid-weak base titrations, the pH at the equivalence point is not 7 but below it. This is due to the production of a conjugate acid during the titration; it will react with water to produce hydronium ions.

3 0

3 years ago

All but one product of the light dependent reaction of photosynthesis is utilized in the light independent reaction. That is

harina [27]

Answer: ATP Adenosine triphosphate

Explanation: During light reaction plants produce glucose and as well as ATP and NADPH as another products. Now during the Dark or light independent reaction there is no presence of light energy to fuel the process so ATP is used as an alternative to fix CO2 molecules.

5 0

3 years ago