What happens to mass and energy in a closed system?

The molar mass of the compound was found to be 30.069 g/mol. what is the molecular formula? express your answer as a chemical fo

kodGreya [7K]

For us to accurately determine what compound this is, additional info must be given. However I can suggest two compounds which have molecular mass of about 30.07 g/mol.

1. It could be NO or nitric oxide.

The molecular mass is 16 + 14= 30 g/mol

But if we search the exact weight, it is 30.01 g/mol

2. It could also be (CH3)2 or ethane.

The molecular mass is 2*12+ 6*1= 30 g/mol

But if we search the exact weight, it is 30.07 g/mol.

<span>So we could say it more likely to to be (CH3)2 </span>

6 0

3 years ago

How do you distinguish a chemical change from a physical change

kirill [66]

Answer:

One distinguishing feature between physical and chemical changes is that a physical change can be reverse or turn back to its original form, but chemical change cannot be return to its form because the material change.

Explanation:

7 0

3 years ago

How much heat is needed to melt 10.0 grams of ice at -10°C until it is water at 10°C?

zhannawk [14.2K]

The heat needed to melt 10.0 grams of ice at -10°C until it is water at 10°C is 3,969.5 J. (approx= 3963J).

<h3>What is Sensible heat? </h3><h3 />

Sensible heat is defined as the amount of heat that a body absorbs or releases without any changes in its physical state.

Q= c×m×∆T

<h3>What is Latent heat? </h3><h3 />

Latent heat is defined as the energy required by a quantity of substance to change state.

When this change consists of changing from a solid to a liquid phase, it is called heat of fusion and when the change occurs from a liquid to a gaseous state, it is called heat of vaporization.

In this case, the heat Q that is necessary to provide for a mass m of a certain substance to change phase is equal to

Q= m×L

Where,

L is the latent heat

C= specific heat capacity of ice= 2.108 J/gK

M= 10 g

ΔT= T(final)– T(initial) = 0 °C – (-10 °C)= 10 °C= 10 K

Sensitive heat Q(1) = 2.108×10×10

= 210.8J

<h3>Heat needed to melt ice</h3><h3 />

The specific heat of melting of ice is 334 J/g, the heat needed to melt 10 grams of ice is

Q(2) = 10× 334

= 3340J

C= specific heat capacity of liquid water is 4.187 J/gK

M= 10 g

ΔT= T(final) – T(initial) = 10 °C – 0 °C= 10 °C= 10 K because being a temperature difference, the difference is the same in °C and K.

Q(3) = 4.187×10×10

= 418.7 J.

Total heat required= Q1 + Q2 + Q3

Total heat required= 210.8 J + 3,340 J + 418.7 J

= 3969.5J

Thus, the heat needed to melt 10 gram of ice from temperature-10°C to 10°C is 3969.5. Therefore, option B is correct option.

learn more about heat :

brainly.com/question/16818736

#SPJ1

8 0

2 years ago

Compared to the particles in a gas, the particles in a solid move

pentagon [3]

B. Slower than the gas is the answer

3 0

2 years ago

think about the statement "there is no new water on earth" write at least 5 sentences describing how there can be no new water o

Vinil7 [7]

Earth contains huge quantities of water in its oceans, lakes, rivers, the atmosphere, and believe it or not, in the rocks of the inner Earth. Over millions of years, much of this water is recycled between the inner Earth, the oceans and rivers, and the atmosphere. This cycling process means that freshwater is constantly made available to Earth's surface where we all live. Our planet is also very efficient at keeping this water. Water, as a vapor in our atmosphere, could potentially escape into space from Earth. But the water doesn't escape because certain regions of the atmosphere are extremely cold. (At an altitude of 15 kilometers, for example, the temperature of the atmosphere is as low as -60° Celsius!) At this frigid temperature, water forms solid crystals that fall back to Earth's surface.
Many people live faraway from freshwater sources. They need to carry their water home.
While our planet as a whole may never run out of water, it's important to remember that clean freshwater is not always available where and when humans need it. In fact, half of the world's freshwater can be found in only six countries. More than a billion people live without enough safe, clean water.
Also, every drop of water that we use continues through the water cycle. Stuff we put down the drain ends up in someone or something else's water. We can help protect the quality of our planet's freshwater by using it more wisely.

8 0

2 years ago