Liquid nitrogen can be used as a cryogenic substance to obtain low temperatures. Under atmospheric pressure, liquid nitrogen boils at 77 K, allowing low temperatures to be reached. However, if the nitrogen is placed in a sealed, insulated container connected to a vacuum pump, even lower temperatures can be reached. Why? If the vacuum pump has sufficient capacity and is left on for an extended period of time, the liquid nitrogen willstart to freeze. Explain.

Q: Four liquids are described in the table below. Use the second column of order of their boiling…

A:

Q: The phase diagram for helium is shown. Liquid  helium can exist in two possible forms; Helium II and…

A: Boiling point is the temperature where liquid converts to vapour state and is achieved when the…

Q: In the given phase diagram below, under normal conditions, what is the freezing point of the…

A: Since the solid phase and liquid phase, both will have equilibrium at a freezing point.

Q: Explain the difference between evaporation below the boilingpoint of a liquid and evaporation at the…

A: Firstly we have to understand the term evaporation and boiling point.  Evaporation occurs at all…

Q: The substance oxygen has the following properties: normal melting point: 54.8 K normal boiling…

A:

Q: A refrigerator cools by evaporating liquefied dichlorodifluoromethane, CCl2F2. How many kilograms of…

A: The mass of water is 525 g and the molar mass of water is 18.02 g/mol. Using the relation between…

Q: When thermal energy is supplied to melt a solid, the temperature remained constant during the…

A: Melting point is the temperature of a solid at which it changes its state from solid to liquid at…

Q: Which liquid is more viscous at room temperature,water or molasses? Explain.

A: Viscosity means the internal resistance between the layer of the liquids. The higher the resistance…

Q: Carbon tetrachloride has a vapor pressure of 213 torr at 40.°C and 836 torr at 80.°C. What is the…

A:

Q: Arrange these substances in order of increasing boiling point utilizing the concept of…

A: Boiling point of a substance is defined as the temperature at which the vapour pressure of liquid…

Q: How much energy is released when 34.8 g of water freezes? The heat of fusion for water is 6.02…

A: The Given data- The mass of water = 34.8 g. The heat of fusion = 6.02 kJ/mol. to determine = The…

Q: Which substance can have dipole-dipole attraction between its molecules? O Br 2 O CH3CH 20H CCI 4 CH…

A: Br2 is a nonpolar molecule. Its strongest intermolecular forces are London dispersion forces.…

Q: What are the strongest attractive intermolecular forces found in: b. bromine:- а. ice:- С. СаCl2:-…

A: Intermolecular forces are the forces of attraction between the different molecules. There are five…

Q: 12.) which has lowest boiling point according to ta ble? Vapor pressure at 376mmHq) 23 Substonce ||…

A: Given Substance Vapor pressure at 25°C (in mmHg) I 23 II 650 III 92 IV 139 Which has…

Q: The molar heat of fusion of sodium metal is 2.60 kJ/mol, whereas its heat of vaporization is 97…

A: The required heat amount for altering the substance's state from one into another state is termed as…

Q: Explain why the temperature remains constant during the process of melting and condensation.

A: The temperature remains constant during the process of melting because the physical state of the…

Q: The energy that must be added to convert exactly 1 g of solid to liquid at the melting point…

A: Latent heat is defined as the heat required to change the state of 1gram of matter,without changing…

Q: The greater the molar heat of vaporization of a liquid, the greater its vapor pressure. Is this true…

A: We are authorised to solve only one question at a time. Please post rest of the questions…

Q: Describe the intermolecular forces that must be overcome to convert each of the following from a…

A: As you have posted 2 questions, and have not mentioned which question you want us to solve, hence we…

Q: How much water at its boiling point can be vaporized by adding 1.50kJ of heat?

A: Given that, q =  1.5 kJ heat is added to water at boiling point 1000C. Heat of vaporization of water…

Q: following standard boiling points are given (at 1 atm): (a) water, 100°C…

A: Answer is d) diethyl ether CH3-CH2-OCH2-CH3

Q: What phase occurs when a block of dry ice gradually becomes foglike at room temperature?

A: Sublimation is a process of conversion of a solid substance directly into gas without changing into…

Q: Which is the solid-gas coexistence curve? Which point marks the highest temperature and pressure at…

A: Phase diagram of water is a pressure-temperature diagram, that represents various phases of water…

Q: Based on the phase diagram for water, explain how it is possible to skate on ice, that is, solid…

A: Phase diagrams: The different phases of a system can be represented in a diagram called a phase…

Q: You have ice at 263 K (-10.0 oC) and 1.0 atm. What could you do to make the ice sublime?

A: The phase diagram of water is shown below.

Q: Carbon tetrachloride displays a triple point at 249.0 K and a melting point (at 1 atm) of 250.3 K.…

A: The temperature at which the solid transform into liquid is called melting point.

Q: Consider the organic compounds ethanol (CH3CH2OH) and ethanethiol (CH3CH2SH). a)Draw Lewis…

A:

Q: what quantity of heat would be required to vaporize 2.30g of aluminum at its normal boiling point?

A: the answer is follows as :

Q: Although steel is denser than water, a steel needle or paper clip placed carefully lengthwise on the…

A: We know that , A metal needle or paper clip has higher density that of water. So when it is dropped…

Q: What is represented by point D on the phase diagram? A) melting point B) triple point B A C) boiling…

A: Phase diagram A diagram which shows the solid, liquid and gaseous phase of a substance at different…

Q: List the following substances in order of increasing normal boiling points, Tb, and explain your…

A: The boiling point of a  molecule is determined by the intermolecular forces present between them.…

Q: The boiling points of some common substances are as follows: Ethanol, C2H5OH 78.4°C Ethylene glycol,…

A:

Q: How much ice (in grams) would have to melt to lower the temperature of 351 mL of water from 26 oC to…

A: Given,Volume of water = 351mL.Initial temperature = 260C.Final temperature = 40C.

Q: The substance oxygen has the following properties: normal melting point: 54.8 K normal boiling…

A: Melting point: Temperature below which liquid phase of molecule converts in solid phase and at this…

Q: Arrange the following compounds in a vertical list from highest boiling point (top) to lowest…

A: Cu is  known as copper  O2  is  known as oxygen  KF is known as pottasium flouride NH3 is know as…

Q: Argon has normal boiling and freezing points of 87.3 K and 83.8 K, respectively. The triple point of…

A: All the necessary calculations have been done in the following step.

Q: Compound y has a heat of fusion of 361 J/g. The solid form has a specific heat capacity of 0.353…

A:

Q: How much energy would need to be added to 930.g of ice at 0.0°C to turn it into liquid water at…

A:

Q: What is the dominant force holding the units together in solid benzoic acid?

A: Intermolecular force present in benzoic acid

Q: Compounds like CCl2F2 are known as chlorofluorocarbons,or CFCs. These compounds were once widely…

A: Given The heat of vaporization of CCl2F2 is 289J/g. The mass of water is 200g. The heat of fusion of…

Q: Compounds like CCl2F2 are known as chlorofluorocarbons, or CFCs. These compounds were once widely…

A: Amount of heat released when 201g of water freezes:

Q: Equal amounts of which of the following substances would have the highest vapor pressure at 75°C?…

A: Strongest the intermolecular forces of attraction, lowest the vapour pressure. All the molecule…

Q: Oose the substance with the highest vapor pressure at a mperature. SiS2 CH3SCH3 RbCl BF3 S6H3

A: The substance with the weakest intermolecular attraction will have highest vapor pressure. SiS2 is a…

Q: 1. Does the diagram best describe a crystalline solid, a liquid, or a gas? Explain.  2. In terms of…

A: Both a conventional fluid and a nematic fluid precious stone stage are liquids, however just in a…

Q: 1. Describe the nature of liquids by relating it with intermolecular attractive forces. 2. Explain…

A: Intermolecular forces are electrostatic in nature and include vanderwaals forces and hydrogen bond .…

Q: What mass of this substance must evaporate to freeze 210 gg of water initially at 25 ∘C∘C? (The heat…

A:

Q: Use the vapor-pressure curve in Figure 11.22 to estimate the external pressure under which ethyl…

A: We would use the given curve to answer these questions.

Q: The vapor pressure of liquid acetone, CH3COCH3, is 40.0 mm Hg at 264 K. A sample of CH;COCH3 is…

A: Given: The vapor pressure of the liquid acetone, CH3COCH3 is 40.0 mm Hg at 264 K.

Q: Which evaporates more quickly: 55 mL of water (H2O) in a beaker or 55 mL of acetone [(CH3)2CO] in an…

A: Any liquid starts to boil when its vapor pressure equals the atmospheric pressure. Imagine an…

Crystal Structures

Solids are present all around us. They have different properties and applications. Diamond and graphite are two well-known solids. Diamond is the hardest material in the world and is used in making jewelry. Graphite on the other hand is soft. The lead of your pencil is graphite. Why are they so different in appearance and properties despite the fact they are chemically the same? Both are allotropes of carbon. The answer lies in the structure, the way constituent particles are arranged in the solids.