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Irina-Kira [14]
3 years ago
7

Explain why seeing a gas doesn not always indicate that there was a chemical change. ​

Chemistry
1 answer:
Orlov [11]3 years ago
7 0
A change of state (which is a physical change) can cause gas.
You might be interested in
Which statement correctly compares ice and liquid water?
Evgen [1.6K]

Answer:

B. Particles of liquid water have more energy than particles of ice.

Explanation:

We can work this out through eliminating the wrong statements.

A. Both liquid water and ice have definite shapes.

This is wrong because, as stated in the question, water is a liquid, and one of the properties of liquids is that they change shape to fit the shape of their container. If it changes shape, it does not have a "definite" shape.

B. Particles of liquid water have more energy than particles of ice.

This is correct, and here is why. There are 3 states of matter: solid, liquid and gas. As you apply heat energy to an object at each state, the particles receive more energy and can move around more (this is kinetic energy). In the case of liquid (water) and solid (ice), particles in solids do not have much energy and stay in rigid formations. They do vibrate slightly, but only on the spot (this is what gives solids "definite" shapes). On the other hand, particles in liquids have more energy than particles in solids, which means that they can move more (more kinetic ENERGY) and do not stay in formations (this is why they do not have "definite" shapes). Therefore, particles in liquids (water) have more energy than particles in solids (ice), and this statement is correct.

C. Liquid water has a lower temperature than ice.

This is wrong because liquids have more energy than solids. As explained earlier, the reason why particles in liquids have more energy is because more HEAT energy has been applied to them. In the same way, solids have less energy because less HEAT energy has been applied to them. Less heat means a lower temperature. (Also you can use common sense for this one, ice feels colder than liquid water, right?)

D. Ice has a definite volume, but liquid water does not.

This is wrong because of the law of conservation of mass. This law states that particles (or matter or volume) cannot be created or destroyed. When ice melts and becomes liquid water, it has not lost volume: the particles have just gained more energy. This question is most likely there to confuse you, because all substances have definite volumes.

I hope this helps!

5 0
3 years ago
The reaction can be described using the equation: 2C2H25O24CO22H2O. How much C2H2is needed to react with 68.1 g of O2to produce
Sophie [7]

Answer:

22.13g

Explanation:

We'll begin by writing a balanced equation for the reaction. This is illustrated below:

2C2H2 + 5O2 —> 4CO2 + 2H2O

Next, we'll calculate the mass of C2H2 and O2 that reacted from the balanced equation. This is illustrated below:

Molar Mass of C2H2 = (12x2) + (2x1)

= 24 + 2 = 26g/mol

Mass of C2H2 that reacted from the balanced equation = 2 x 26 = 52g

Molar Mass of O2 = 16x2 = 32g/mol

Mass of O2 that reacted from the balanced equation = 5 x 32 = 160g

Now, we can obtain the mass of C2H2 that will react with 68.1g of O2 as follow:

From the balanced equation above,

52g of C2H2 reacted with 160g of O2.

Therefore, Xg of C2H2 will react with 68.1g of O2 i.e

Xg of C2H2 = (52x68.1)/160

Xg of C2H2 = 22.13g

Therefore, 22.13g of C2H2 is needed to react with 68.1g of O2

8 0
3 years ago
What might happen if you got too close to the center of the Milky Way galaxy?
Lady_Fox [76]

Answer:

you would be trapped in the gravitational pull of a black hole

Explanation:

there is a black hole in the center of the galacy

5 0
3 years ago
A lithium atom has three protons, three neutrons, and three electrons. what is the overall charge on this atom? a–3 b 0 c 1 d 3
fredd [130]

  Lithium atomic number = 3

  Li atom has 3 protons,3 electrons.Then it has no charge.

So the charge of Li atom here is zero.

<u>Option b: 0 is the right answer.</u>

5 0
3 years ago
Read 2 more answers
A compound is 40.0% c, 6.70% h, and 53.3% o by mass. assume that we have a 100.-g sample of this compound. the molecular formula
atroni [7]
<span>When you have 100 g of compound, then based on the percentages given, there are 40.0 g C, 6.70 g H, and 53.3 g O. Convert those to moles:

</span>C: 40.0 g / 12.0 = 3.33 moles of C 
<span>H: 6.70 g / 1.01 = 6.63 moles of H </span>
<span>O: 53.3 / 16.0 = 3.33 moles of O 
</span>
<span>Dividing by the smallest (3.33), we get a C:H:O mole ratio of 1:2:1
</span>So, <span>The empirical formula is CH2O.
Now, </span><span>That formula has a molar mass of [12.0 + 2(1.0) + 16.0] = 30.0

And we are given it's molar mass is = 240

So, no. of units of CH2O = 240 / 30 = 8

</span><span>8 x CH2O = C8H16O8, and that is the molecular formula.
</span>
C_8H_{16}O_8
3 0
3 years ago
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