Ionic, covalent and metallic. How many of these can form giant structures?

A 2.50-l volume of hydrogen measured at â196 Â°c is warmed to 100 Â°c. calculate the volume of the gas at the higher temperature

ivann1987 [24]

To solve this we assume that the hydrogen gas is an ideal gas. Then, we can use the ideal gas equation which is expressed as PV = nRT. At a constant pressure and number of moles of the gas the ratio T/V is equal to some constant. At another set of condition of temperature, the constant is still the same. Calculations are as follows:

T1 / V1 = T2 / V2

V2 = T2 x V1 / T1

V2 = (100 + 273.15) K x 2.50 L / (-196 + 273.15) K

V2 = 12.09 L

Therefore, the volume would increase to 12.09 L as the temperature is increased to 100 degrees Celsius.

5 0

3 years ago

Which of the following substances found in tobacco smoke stimulates the brain? A. acetone B. toluene C. nicotine D. ammonia Plea

Vaselesa [24]

The answer is C. Nicotine is the substance found in tobacco smoke that stimulates the brain.

7 0

3 years ago

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HURRY PLEASE

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

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A system gains 652 kJ of heat, resulting in a change in internal energy of the system equal to +241 kJ. How much work is done?

levacccp [35]

Answer:

-411 kj

Explanation:

We solve by using this formula

∆U = ∆Q + ∆W

This formula is the first law of thermodynamics

Change in internal energy U = +241

Heat gained by system Q = 652

Putting the value into the equation

+241 = 652 + W

Workdone = 241 - 652

Workdone = -411 kj

Since work done is negative it means that work was done by the system

3 0

2 years ago

Many appliances in your home and school use electrical energy. Which of these appliances is intended to convert electrical energ

Solnce55 [7]

Answer:

music amplifier or a loudspeaker

Explanation:

A music amplifier or a loudspeaker are a few devices that convert electrical energy into sound energy.

As it is a well known fact that energy can neither be created nor be destroyed it can only change from one form to the other. As here it is changing from electrical to sound.

6 0

2 years ago