As the molecular weight of alkanes increases, how do the boiling point and
melting point change?
(a) boiling point increases ; melting point increases.
(b) boiling point increases ; melting point increases.
(c) boiling point increases ; melting point decreases
(d) boiling point increases ; melting point increases sequentially for alkanes over
four carbons.

1 Answer

Answer :

boiling point increases ; melting point increases sequentially for alkanes over
four carbons.

Related questions

Description : The branching of alkanes that produces symmetrical structures : (a) raises the boiling point ; raises the melting point (b) raises the boiling point ; lowers the melting point (c) lowers the boiling point ; lowers the melting point (d) lowers the boiling point ; raises the melting point

Last Answer : raises the boiling point ; raises the melting point

Description : Which statements about alkenes and alkanes of corresponding chain lengths is true? (I) Alkenes have slightly lower melting points than alkanes (II) Alkenes have slightly higher melting points than alkanes (III) Alkenes have higher boiling ... (a) I and III (b) II and IV (c) I and IV (d) II and III

Last Answer : I and III

Description : Both stearic acid and linoleic acid have 18 carbons. Linoleic acid is unsaturated, while stearic acid is saturated. The melting point of stearic acid : (a) is higher than linoleic acid (b) is lower than linoleic acid (c) is same as linoleic acid (d) can not predict, insufficient information

Last Answer : is higher than linoleic acid

Description : How does the melting point of propane and ethane compare? (a) the melting point of propane is greater. (b) the melting point of ethane is greater. (c) the melting points are within 5°C of one another. (d) no relationship exists among these alkanes and their melting point

Last Answer : the melting point of ethane is greater.

Description : Consider the three isomeric alkanes n-hexane, 2,3-dimethylbutane, and 2- methylpentane. Which of the following correctly lists these compounds in order of increasing boiling point? (a) 2,3-dimethylbutane < 2- ... < 2, 3-dimethylbutane < n-hexane (d) n-hexane < 2-methylpentane < 2,3-dimethylbutane

Last Answer : 2,3-dimethylbutane < 2-methylpentane < n-hexane

Description : Which of the following alkanes will have the lowest boiling point? (a) n-Heptane (b) Isopentane (c) n-Hexane (d) Neopentane

Last Answer : Neopentane

Description : Which of the following alkanes will have the highest boiling point? (a) n-Octane (b) Isopentane (c) n-Butane (d) Neopentane

Last Answer : n-Octane

Description : How do the boiling points of butane, propane, and ethane compare? (a) the boiling point of ethane is greatest. b) the boiling point of butane is greatest. (c) the boiling point of propane is greatest. (d) there is no relationship among these three alkanes and their boiling points

Last Answer : the boiling point of butane is greatest.

Description : Which of the following decreases with increase in pressure? (A) Melting point of ice (B) Melting point of wax (C) Boiling point of liquids (D) None of these

Last Answer : (A) Melting point of ice

Description : When pressure is increased the melting point of ice – (1) increases (2) does not change (3) decreases (4) depends on the impurities in the ice

Last Answer : (3) decreases Explanation: In this case. if we increase the pressure on the ice the ice-water system wants to try to lower it again. It can do that by making itself fit into a ... the melting point of ice decreases because of the inversal relationship between the pressure and melting point of ice.

Description : When pressure is increased the melting point of ice (1) increases (2) does not change (3) decreases (4) depends on the impurities in the ice

Last Answer : decreases

Description : Melting point of ice _______. (1) increases with increase of pressure (2) decreases with increase of pressure (3) is independent of pressure (4) None of these

Last Answer : (2) decreases with increase of pressure Explanation: The melting point of ice at 1 atmosphere of pressure is very close to 0 °C (32 °F, 273.15 K); this is also known as the ice point.

Description : __________ increases with increase in pressure. (A) The melting point of wax (B) The boiling point of a liquid (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) and (B)

Description : The high boiling points of alcohols, as compared to the corresponding alkanes, are due to (a) Hydrogen bonding (b) Heavy oxygen atom (c) Water solubility (d) None of these

Last Answer : Hydrogen bonding

Description : Consider a 1°, 2° and 3° amine, all of equivalent molecular weight. Which amine is most likely to have the lowest boiling point? (a) 1° amine (b) 2° amine (c) 3° amine (d) Not enough information to determine

Last Answer : 3° amine

Description : Consider a small aliphatic 1° amine, 1° alcohol, ester, carboxylic acid, and amide, all of similar molecular weight. Which one is most likely to have the highest boiling point? (a) The amide (b) The alcohol (c) The ester (d) The carboxylic acid

Last Answer : The amide

Description : Cycloalkanes have the same molecular formula as : (a) Alkanes (b) Alkenes (c) Alkynes (d) Cycloalkenes

Last Answer : Alkenes

Description : Melting point of ice _______. (1) increases with increase of pressure (2) decreases with increase of pressure (3) is independent of pressure (4) None of these

Last Answer : (2) decreases with increase of pressure Explanation: The melting point of ice at 1 atmosphere of pressure is very close to 0 °C (32 °F, 273.15 K); this is also known as the ice point.

Description : The presence of impurities in iron (A) Increases its melting point (B) Does not affect its melting point (C) Decreases its melting point (D) Makes it malleable

Last Answer : (C) Decreases its melting point

Description : As the impurities are oxidised, the melting point of iron (A) Decreases (B) Remains unchanged (C) Increases (D) May increase or decrease; unpredictable

Last Answer : (C) Increases

Description : The melting point of paraffin wax (which contracts on solidification) __________ with pressure rise. (A) Increases (B) Decreases (C) Remains unchanged (D) Decreases linearly

Last Answer : (A) Increases

Description : Viscosity of a polymer solution or melt (A) Decreases with increase in molecular weight (B) Decreases with increase in temperature (C) Increases with increase in temperature (D) Does not vary with temperature rise

Last Answer : (C) Increases with increase in temperature

Description : Choose the correct statement. (A) Coking tendency increases with increasing molecular weight (B) Coking tendency decreases with increasing molecular weight (C) Higher pressure enhances coke formation (D) Coking is an exothermic reaction

Last Answer : (A) Coking tendency increases with increasing molecular weigh

Description : With increase in the molecular weight of aromatic present in kerosene, its smoking tendency (A) Increases (B) Decreases (C) Remain same (D) Is unpredictable

Last Answer : (A) Increases

Description : Pick out the correct statement. (A) Diffusivity decreases with increase in temperature (B) Diffusivity increases with increase in molecular weight (C) Diffusivity increases with the size of the individual molecule (D) None of these

Last Answer : (D) None of these

Description : C.V. (kcal/Nm3 ) of gaseous fuels __________ with increase in molecular weight. (A) Decreases (B) Increases (C) Remain constant (D) May increase or decrease, depends on combustibles

Last Answer : (D) May increase or decrease, depends on combustibles

Description : Infrared spectroscopy provides valuable information about A. Molecular weight B. Melting point C. Conjugation D. Functional groups

Last Answer : Functional groups

Description : Which of the following best explains why the melting points of saturated fats increase with increasing molecular weight? (a) decreased hydrogen bonding (b) increased hydrogen bonding (c) decreased intermolecular van der Waal’s interactions (d) increased intermolecular van der Waal’s interactions

Last Answer : increased intermolecular van der Waal’s interactions

Description : The melting points of aldehydes and ketones tend to : (a) decrease with increasing molecular weight. (b) increase with increasing molecular weight. (c) remain unchanged with increasing molecular weight. (d) be unpredictable due to resonance

Last Answer : increase with increasing molecular weight.

Description : Vegetables are cooked in lesser time by adding a pinch of salt while cooking because (1) boiling point of water increases (2) latent heat of vaporization of water decreases (3) latent heat of vaporization of water increases (4) boiling point of water decreases

Last Answer : (1) boiling point of water increases Explanation: Adding salt raises the boiling point of water, which allows food to cook at higher temperature. The higher the temperature, the higher the rate of heat transfer between the food and water, thus it cooks more quickly.

Description : At boiling point of liquids, its : (1) Temperature increases (2) Atmospheric pressure increases (3) Timperature remains increases (4) Vapour pressure decreases

Last Answer : (3) Timperature remains increases

Description : In the pressure cooker, cooking is faster because the increase in vapour pressure - (1) increase the specific heat (2) decreases the specific heat (3) decreases the boiling point (4) increases the boiling point

Last Answer : (4) increases the boiling point

Description : With the increase of pressure, the boiling point of any substance - (1) Increases (2) Decreases (3) Remains Same (4) Becomes zero

Last Answer : (1) Increases Explanation: The temperature stays the same until all the liquid has vaporized. As the temperature of a liquid rises, the pressure of escaping vapor also rises, and at the boiling point ... vapor is equal to that exerted on the liquid by the surrounding air, causing bubbles to form.

Description : At boiling point of liquids, its – (1) Temperature increases (2) Atmospheric pressure increases (3) Temperature remains constant (4) Vapour pressure decreases

Last Answer : (3) Temperature remains constant Explanation: An interesting property of matter is that its temperature remains constant during a phase change, assuming its surrounding pressure is constant. A liquid changes into gaseous state at a constant temperature called its boiling point.

Description : With the increase of pressure, the boiling point of any substance – (1) Increases (2) Decreases (3) Remains Same (4) Becomes zero

Last Answer : (1) Increases Explanation: The temperature stays the same until all the liquid has vaporized. As the temperature of a liquid rises, the pressure of escaping vapor also rises, and at the boiling point ... vapor is equal to that exerted on the liquid by the surrounding air, causing bubbles to form.

Description : Boiling point elevation of an ideal solution (A) Increases rapidly with temperature rise (B) Decreases rapidly with temperature rise (C) In independent of pressure (D) Both (B) and (C)

Last Answer : (A) Increases rapidly with temperature rise

Description : Vegetables are cooked in lesser time by adding a pinch of salt while cooking because (1) boiling point of water increases (2) latent heat of vaporization of water decreases (3) latent heat of vaporization of water increases (4) boiling point of water decreases 

Last Answer :  boiling point of water increases

Description : At boiling point of liquids, its (1) Temperature increases (2) Atmospheric pressure increases (3) Temperature remains constant (4) Vapour pressure decreases 

Last Answer : Temperature remains constant

Description : An optically active compound (a) must contain atleast four carbons (b) when in solution rotate the plane of polarized light (c) must always contain an asymmetric carbon atom (d) in solution always give a negative reading in polarimeter

Last Answer : when in solution rotate the plane of polarized light

Description : What is the I-U-P-A-C (pron: eye-you pack) name for a cyclic alkane containing four carbons?

Last Answer : ANSWER: CYCLOBUTANE

Description : If the boiling point of ethanol (molecular weight `= 46`) is `78^@ C`, the boiling point of dimethyl ether (molecular weight `= 46`) is

Last Answer : If the boiling point of ethanol (molecular weight `= 46`) is `78^@ C`, the boiling point of dimethyl ether (molecular ... ` C. `86^(@)C` D. `34^(@)C`

Description : Asserion (A): The boiling point of `C_(2)H_(5)OH` is less than that of `H_(2)O` though the molecular weight of `C_(2)H_(5)OH` is more than that of wat

Last Answer : Asserion (A): The boiling point of `C_(2)H_(5)OH` is less than that of `H_(2)O` though the molecular ... but R is false D. A is false but R is true

Description : Why is ethanol boiling at a higher boiling point than methyl ether boils at a lower boiling point despite the fact that they have the same molecular weight?

Last Answer : Need answer

Description : Asphalts are (A) Low molecular weight & low boiling point compounds present in petroleum (B) Desirable in catalytic cracking feedstock, because they produce coke (C) Readily oxidisable and form carbonaceous sludge (D) All (A), (B) & (C)

Last Answer : (C) Readily oxidisable and form carbonaceous sludge

Description : How many alkanes (only structural isomers) are possible with the molecular formula `C_(4)H_(8)`

Last Answer : How many alkanes (only structural isomers) are possible with the molecular formula `C_(4)H_(8)` A. 4 B. 3 C. 5 D. 6

Description : What are melting points and boiling points ? What is melting point and boiling point ?

Last Answer : Melting point refers to the process of melting a solid into a liquid at a certain temperature. Boiling point is the temperature at which a liquid evaporates. Therefore , the temperature at which a liquid begins to evaporate is called the 'boiling point' of that substance.

Description : Metals have ______. (1) High melting and boiling point (2) Low melting and boiling point (3) High melting and low boiling point (4) Low melting and high boiling point

Last Answer : (1) High melting and boiling point

Description : (a) What effect the branching of an alkane has on its melting point? (L-III) (b) Which of the following has highest boiling point?(L-III) (1) 2-methyl pentane. (2) 2, 3-diethyl butane. (3) 2, 2- dimethyl butane.

Last Answer : Ans.(a) In general conception, as the branching increases packing of the molecules in the crystals becomes less close and have melting point decreases accordingly. (b) As the branching increases, ... attraction decreases and hence the boiling point decreases. So, 2-methyl pentane has highest B.pt.

Description : Which of the following is not true of enantiomers? (a) They have the same melting point. (b) They have the same boiling point. (c) They have the same density. (d) They have the same specific rotation.

Last Answer : They have the same specific rotation.

Description : Define the following : Sublimation , Melting Point , Fusion , Evaporations , Boiling Point , Vapourization , Condensation , Deposition.

Last Answer : Ans : Sublimation : Sublimation is the process in which some solids upon heating instead of changing into liquid state are converted directly into gaseous (vapour) state. Example : Ammonium Chloride ... happens from the gaseous phase into the solid phase directly, the change is called deposition.