States Of Matter

In lithium crystal, free electrons are present, hence, Li has high thermal and electrical conductivity.

• As it is an alkali metal, it has an electron in its outermost orbital.
• Due to the free electrons, it has extremely high electrical and thermal conductivity.

A solid with high electrical and thermal conductivity is Lithium.

Diffusion of Gases Calculation

The ratio of the rates of diffusion of oxygen ( ) and hydrogen ( ) is given by Graham's law of diffusion:

Where: - and are the rates of diffusion of oxygen and hydrogen, respectively, - and are the molar masses of hydrogen and oxygen, respectively.

Substitute the values for the molar masses of hydrogen and oxygen:

This simplifies to:

Calculation of Moles of Diffused

If moles of are diffused in a given time, we can find the moles of diffused in the same time using the ratio:

Conclusion:

The number of moles of oxygen ( ) diffused in the same time is moles.

To determine the correct graphical representation of Boyle's Law, we must first understand the principle of the law itself. Boyle's Law states that for a given mass of gas at constant temperature, the volume of the gas is inversely proportional to its pressure. Mathematically, this is expressed as:

This implies that if you were to plot pressure (P) against volume (V), the graph would be a hyperbola. When different temperature curves are considered, these are called isotherms, and each curve corresponds to a different constant temperature.

Let's analyze each graph option provided:

• Option 1: This graph shows hyperbolic curves as the pressure decreases with an increase in volume, and it includes multiple curves for different temperatures. This correctly represents Boyle's Law.
• Option 2: This graph does not appear to represent the inverse relationship characteristic of Boyle's Law.
• Option 3: This graph again does not show the required hyperbolic relationship.
• Option 4: Similar to options 2 and 3, this graph fails to illustrate the correct inverse relationship between pressure and volume.

Therefore, the correct choice for the graphical representation of Boyle's Law (pressure vs. volume at different temperatures) is:

Conclusion: Option 1 correctly illustrates Boyle's Law, with pressure decreasing as volume increases for different temperatures, shown as a series of hyperbolic curves.

To find the total pressure in the mixture of gases, we can use the ideal gas law. The ideal gas equation is given by:

Where:

• = total pressure
• = volume (in litres)
• = total number of moles of gas
• = universal gas constant,
• = temperature (in Kelvin)

Given:

• Weight of = 4 g
• Weight of = 2 g
• Volume = 1 L
• Temperature = 273 K

First, we calculate the moles of each gas using their molecular weights:

• Molecular weight of = 32 g/mol
• Moles of
• Molecular weight of = 2 g/mol
• Moles of

Total number of moles, , in the mixture is the sum of the moles of and :

We can now substitute the known values into the ideal gas equation to find the total pressure:

Calculate the total pressure:

Rounding to the significant figures based on the options provided, the total pressure is approximately .

This matches with the correct answer choice: 25.18.

To determine the pressure inside the flask, we will use the ideal gas law equation: .
Here, is the pressure, is the volume, is the number of moles, is the ideal gas constant, and is the temperature in Kelvin.
First, convert the mass of oxygen to moles. The molar mass of is approximately 32 g/mol.

Next, convert the temperature from Celsius to Kelvin: .
Now, substitute the known values into the ideal gas law:
Rounding to one decimal place, the pressure is approximately 4.9 bar.

To determine the most appropriate answer, we need to analyze both the assertion and the reason given.

Assertion (A): In a particular point defect, an ionic solid is electrically neutral, even if few of its cations are missing from its unit cells.

Explanation of (A): If cations are missing, such a point defect is known as a Schottky defect. In a Schottky defect, equal numbers of cations and anions are missing, preserving the overall electrical neutrality of the ionic solid. Therefore, the assertion is correct because the absence of some cations does not disturb the electrical neutrality as enough number of anions are also absent.

Reason (R): In an ionic solid, Frenkel defect arises due to dislocation of cation from its lattice site to interstitial site, maintaining overall electrical neutrality.

Explanation of (R): A Frenkel defect involves a cation moving from its regular lattice position to an interstitial site, leading to a dislocation and not a loss of cations from the crystal structure. Thus, electrical neutrality is maintained in Frenkel defects as no ions are actually lost from the crystal. Therefore, the reason is also correct.

However, the given reason does not directly explain the assertion correctly. The assertion mentions the absence of cations which correlates with Schottky defect, not Frenkel defect.

Thus, the proper conclusion is:

Both (A) and (R) are correct and (R) is not the correct explanation of (A)

Intermolecular forces are the forces of attraction or repulsion between molecules. These forces determine many physical properties of substances, such as boiling points, melting points, and solubility. Let’s go over the different types of intermolecular forces mentioned:

Types of Intermolecular Forces

• Dipole-Dipole Attraction: This occurs when two or more polar molecules come into contact. The positive end of one molecule attracts the negative end of another, resulting in a dipole-dipole attraction.
• Dipole-Induced Dipole Attraction: This happens when a polar molecule induces a dipole in a nonpolar molecule. The polar molecule causes the nonpolar molecule to have a temporary dipole, leading to attraction.
• Hydrogen Bonding: This is a special type of dipole-dipole attraction where hydrogen is bonded to a highly electronegative element (such as oxygen, nitrogen, or fluorine). This results in a strong intermolecular force.
• Dispersion Forces (London Dispersion Forces): These are the weakest intermolecular forces and occur primarily between nonpolar molecules. They are caused by temporary fluctuations in electron distribution within molecules, which create instantaneous dipoles.
• Covalent Bonds: Covalent bonds are not intermolecular forces; they occur between atoms within a molecule, where electrons are shared between atoms.

Conclusion

Based on the explanation above, the correct options are:
- A: Dipole-Dipole Attraction is correct.
- B: Dipole-Induced Dipole Attraction is correct.
- C: Hydrogen Bonding is correct (it is a special form of dipole-dipole interaction).
- E: Dispersion Forces are correct (they function between nonpolar molecules).

Final Answer:

The correct option is (B): A, B, C, E are correct.

Boyle's Law is a fundamental principle in chemistry and physics that describes the relationship between the pressure and volume of a gas at constant temperature. It can be mathematically expressed as:

PV = k

Where:

• P is the pressure of the gas.
• V is the volume of the gas.
• k is a constant.

Boyle's Law implies that pressure and volume are inversely proportional when temperature is held constant. This means if the volume increases, the pressure decreases, and vice versa, as long as the temperature does not change. The graphical representation of this inverse relationship is a curve (hyperbola) that starts high and slopes downwards, suggesting that when one parameter increases, the other decreases.

The correct option displays a graph of Pressure (P) versus Volume (V) showing a downward curve, which is characteristic of this inverse relationship.