All of the following are reasons why equations or balanced EXCEPT

katrin2010 [14]

Answers:

Question 1:

The diagram for gallium will have flat, horizontal lines at 30 and 2204 °C.

Questoin 2:

The diagram for methane will have a diagonal line representing the liquid phase between -183°C and -162°C.

Question 3:

For gold, the boiling point corresponds to the y-value at 2856 °C of the top horizontal line

Question 4.

For nitrogen, the line at -210°C will be flat, which represents the change from a solid to a liquid

Explanations:

Question 1:

The diagram for gallium will have flat, horizontal lines at 30 and 2204 °C.

The table shows that the melting point of gallium is 30°C and its boiling point is 2204°C.

Melting point is the temperature at which the substace changes its state from solid to liquid. During that change, the temperature of the substance does not change, because the heat supplied is used to accomplish the phase change. So, the temperature is constant and that means that portion of the diagram is flat.

The same is valid during boiling: the temperature remains constant while the substance is passing from liquid to gas at the boiling point.

Questoin 2:

The diagram for methane will have a diagonal line representing the liquid phase between -183°C and -162°C.

Between the melting (-183°C) and boiling (-162°C) points of methane, its temperature will increase more or less linearly, which is represented with a diagonal (slant) line between those points. During this interval the heat is used to increase the temperature and no phase of change happens.

Question 3:

For gold, the boiling point corresponds to the y-value at 2856 °C of the top horizontal line

The table shows that the boiling point of gold is 2,856°C.

In a temperature-vs.-time diagram the temperature is represented on the vertical axis (y-value) and the time is represented on the horizontal axis.

Since, the temperature of the substance does not change during boiling, the line during the time that this change of phase is happening is flat. And since this temperatue is higher than the melting temperature, this is the top horizontal line in the diagram.

Question 4.

For nitrogen, the line at -210°C will be flat, which represents the change from a solid to a liquid

The table shows that the melting point of nitrogen is -210°C, that means that the temperature will remain constant at -210°C while the substance is absorbing heat to pass from solid to liquid.

In conclusion, you must remember that all the phase changes, melting (from solid to liquid), freezing (from liquid to solid), boilng (from liquid to gas), and condensing (from gas to liquid) happens at constant temperature, and so the temperature - vs. - time diagrams show flat lines (constant y-values) during those intervals of time.

4 0

2 years ago

Read 2 more answers

Is the electrolysis of water an oxidation-reduction reaction??

QveST [7]

Answer:

Yes

Explanation:

Electrolysis is an example of redox reaction because reduction takes place at cathode and oxidation takes place at anode and both of these reactions take place simultaneously.

8 0

2 years ago

Which of the following compounds is a gas at room temperature? A : CH3CH2OH B : CH3CH2CH2CH2CH2CH2CH3 C : CH3CH2CH3 D : HOCH2CH2

attashe74 [19]

Answer:

C. $CH_3CH_2CH_3$

Explanation:

Molecules with the stronger intermolecular forces are pulled tightly together to form solid at higher temperatures and that's why the freezing point is higher.

Also, molecules with the stronger intermolecular force have greater interaction between the molecules and thus on heating do not boil easily and have high boiling point also.

Thus, melting point and boiling point increases with increase in number of carbon atoms and also increase in intermolecular forces (like hydrogen bonding, if present).

Thus, the compound which is gas at room temperature is $CH_3CH_2CH_3$ because it has least number of carbon atoms and absence of hydrogen bonding.

8 0

3 years ago

What is the molarity of a solution that contains 1.67 moles in 1,750 mL?

solmaris [256]

Answer:

0.954M solution

Explanation:

molarity = moles solute / volume solution in liters

=> molarity = 1.67 moles / 1.750 L soln = 0.954M solution

8 0

2 years ago

You have a mixture that contains 0.380 moles of Ne(g), 0.250 moles of He(g), and 0.500 moles CH4(g) at 400 K and 6.25 atm. What

Bas_tet [7]

Answer:

1.38 atm

Explanation:

Partial pressure of a gas = total pressure × mole fraction of that gas.

Mole fraction of a gas is moles of a gas ÷ total moles of all gases.

4 0

2 years ago