All categories

3 years ago

Why do some obejects such as door and windows get bigger and smaller?

1 answer:

4 0

<span>It's because they expand in the heat of the summer and contract during the cold winter. Everything on Earth is made up of tiny particles called molecules, which are in constant motion. When the molecules heat up, they move faster, pulling apart from one another.</span>

You might be interested in

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

I need help with this question

malfutka [58]

What question do you need help with

5 0

3 years ago

Read 2 more answers

A gas occupies 13.2 L at a pressure of 2.36 atm. What is the pressure of the gas if the volume is 2.13 L and the temperature rem

Wewaii [24]

Answer:

the pressure is to tight needs to be looser 13.2L of 2.36 and 2.13L

5 0

2 years ago

How could you calculate the number of grams of O2 needed to completely react with a certain amount of ethane?

natima [27]

First, write out a complete balanced reaction for the combustion of ethane, ethane + O2 -> CO2 + H20. Then, divide the grams of ethane by its Molar Mass and multiply by 32, the molar mass of O2.

3 0

4 years ago

One of the characteristics of an acid-base reaction is that this type of reaction forms water true or false

Julli [10]

True! Acid-base reactions will always form water and a salt (not necessarily table salt, though!).

4 0

3 years ago