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Which of the following pairs of gases is mainly responsible for green house effect? (1) Ozone and Ammonia (2) Oxygen and Nitrogen (3) Nitrogen and Sulphur dioxide (4) Carbon dioxide and Methane

The freezing point depression constant for water is $1.86 ^\circ\text{C m}^{-1}$. If $5.00 \text{ g}$ $Na_2SO_4$ is dissolved in $45.0 \text{ g}$ $H_2O$, the freezing point is changed by $-3.82 ^\circ\text{C}$. The Van’t Hoff factor for $Na_2SO_4$ is:

Zr ($Z = 40$) and Hf ($Z = 72$) have similar atomic and ionic radii because of:

The freezing point depression constant for water is $1.86^\circ\text{C m}^{-1}$. If $5.00 \text{ g Na}_2\text{SO}_4$ is dissolved in $45.0 \text{ g H}_2\text{O}$, the freezing point is changed by $-3.82^\circ\text{C}$. Calculate the van't Hoff factor for $\text{Na}_2\text{SO}_4$.

$1.00 \text{ g}$ of a non-electrolyte solute (molar mass $250 \text{ g/mol}$) was dissolved in $51.2 \text{ g}$ of benzene. If the freezing point depression constant, $K_f$ of benzene is $5.12 \text{ K kg mol}^{-1}$, the freezing point of benzene will be lowered by:

When 5 g of non-volatile non-electrolyte solute is dissolved in 100 g of a certain solvent, the freezing point of the solvent decreases by 0.25 K. The molar mass of the solute is: [$K_f$ of the given solvent = $1.2 \text{ K kg mol}^{-1}$]

Which of the following aqueous solutions of electrolytes will exhibit the least elevation in boiling point?

The vapour pressure of a solvent decreases by 10 mm Hg when a non-volatile solute is added to the solvent. The mole fraction of the solute in the solution is 0.2. What would be the mole fraction of the solvent if the decrease in vapour pressure is to be 20 mm Hg?

The mixture that shows positive deviation from Raoult's law is:

The following solutions were prepared by dissolving 10 g of glucose ($C_6H_{12}O_6$) in 250 ml of water ($P_1$), 10 g of urea ($CH_4N_2O$) in 250 ml of water ($P_2$) and 10 g of sucrose ($C_{12}H_{22}O_{11}$) in 250 ml of water ($P_3$). The decreasing order of osmotic pressures of these solutions is:

During osmosis, the flow of water through a semi-permeable membrane is:

Lanthanoid's most common oxidation state is:

Solution of sucrose (Molar Mass = 342 g mol⁻¹) is prepared by dissolving 34.2 g of it in 1000 g of water. Freezing point of the solution is: (K_f for water is 1.86 K kg mol⁻¹)

If the rate constant for a first order reaction is k, the time (t) required for the completion of 99% of the reaction is given by:

At $100^\circ\text{C}$ the vapour pressure of a solution of $6.5 \text{ g}$ of a solute in $100 \text{ g}$ water is $732 \text{ mm}$. If $K_b = 0.52$, the boiling point of this solution will be

A solution of sucrose (molar mass = $342 \text{ g mol}^{-1}$) has been prepared by dissolving $68.5 \text{ g}$ of sucrose in $1000 \text{ g}$ of water. The freezing point of the solution obtained will be: ($K_f$ for water = $1.86 \text{ K kg mol}^{-1}$)

A $0.0020 \text{ m}$ aqueous solution of an ionic compound $\text{Co(NH}_3)_5(\text{NO}_2)\text{Cl}$ freezes at $-0.00732^\circ\text{C}$. Number of moles of ions which $1 \text{ mol}$ of ionic compound produces on being dissolved in water will be ($K_f = 1.86^\circ\text{C m}^{-1}$)

If 8 g of a non-electrolyte solute is dissolved in 114 g of n-octane to reduce its vapor pressure to 80%, the molar mass (in g mol⁻¹) of the solute is: [Molar mass of n-octane is 114 g mol⁻¹]

Given below are two statements: one is labeled as Assertion (A) and the other is labeled as Reason (R): Assertion (A): Helium is used to dilute oxygen in the diving apparatus. Reason (R): Helium has a high solubility in $O_2$. In light of the above statements, choose the correct answer from the options given below:

1% (w/w) solution of a compound is isotonic with 5% (w/w) sucrose (sugar) solution. The molecular weight of the compound will be: