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6 months ago

Chemistry Chemistry Coordination Compounds

. [Ti(H?O)?]³? absorbs light of wavelength 498 nm during a d-d transition. The octahedral splitting energy for the above complex is __________ *10?¹?J. (Round off to the nearest integer).
h = 6.626 * 10?³? Js; c = 3 * 10? ms?¹

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alok kumar singh

Contributor-Level 10

The energy is calculated using the formula Δ? = hc/λ. Plugging in the values for Planck's constant (h), the speed of light (c), and the given wavelength gives an energy of 3.99 * 10? ¹? J. The answer is requested as a single digit.
Answer: 4 (in units of 10? ¹? J)

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6 months ago

Chemistry Solutions

At 363 K, the vapour pressure of A is 21 kPa and that of B is 18 kPa. One mole of A and 2 moles of B are mixed. Assuming that this solution is ideal, the vapour pressure of the mixture is __________ kPa. (Round off to the nearest integer).

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alok kumar singh

Contributor-Level 10

Using Raoult's Law, P_Total = P°_A·X_A + P°_B·X_B = (21 kPa * 1/3) + (18 kPa * 2/3) = 7 + 12 = 19 kPa.
Answer: 19 kPa

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6 months ago

Chemistry Class 11th

At 25°C, 50 g of iron reacts with HCl to form FeCl?. The evolved hydrogen gas expands against a constant pressure of 1 bar. The work done by the gas during this expansion is __________ J. (Round off to the nearest integer).
[Given: R= 8.314 J mol?¹ K?¹. Assume hydrogen is an ideal gas]
[Atomic mass of Fe is 55.85u]

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alok kumar singh

Contributor-Level 10

The reaction is Fe (s) + 2HCl (aq) → FeCl? (aq) + H? (g). 50 g of Fe corresponds to 0.89 moles, which produces 0.89 moles of H? (g). The work done by the gas is calculated using W = -Δn_gasRT. The work done by the gas is the positive value, 2218 J.
Answer: 2218 J

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6 months ago

Chemistry Chemistry Organic Chemistry

In Duma's method of estimation of nitrogen, 0.1840 g of an organic compound gave 30 mL of nitrogen collected at 287 K and 758 mm of Hg pressure. The percentage composition of nitrogen in the compound is __________. (Round off to the nearest integer).
[Given: Aqueous tension at 287K = 14 mm of Hg]

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alok kumar singh

Contributor-Level 10

The partial pressure of dry N? is 758 - 14 = 744 mm Hg. Using the ideal gas law (PV=nRT), the moles of N? are calculated to be 1.25 * 10? ³ mol. This corresponds to 0.035 g of N? The percentage of nitrogen in the sample is (0.035 g / 0.1840 g) * 100, which is 18.96%.
Answer: 19 (Rounded)

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6 months ago

Chemistry Chemistry Solutions

When 35 mL of 0.15 M lead nitrate solution is mixed with 20mL of 0.12 M chromic sulphate solution, __________ *10⁻⁵ moles of lead sulphate precipitate out.

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alok kumar singh

Contributor-Level 10

This is a limiting reactant problem. The initial moles are 5.25 mmol of Pb (NO? )? and 2.4 mmol of Cr? (SO? )? Based on the 3:1 stoichiometric ratio, Pb (NO? )? is the limiting reactant. The moles of PbSO? formed are equal to the initial moles of the limiting reactant, which is 5.25 mmol or 5.25 * 10? ³ moles. The question asks for the answer in units of 10? moles.

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6 months ago

Chemistry Class 12th

Ga (atomic mass 70u) crystallizes in a hexagonal close packed structure. The total number of voids in 0.581 g of Ga is __________ *10²¹. (Round off to the nearest integer).
[Given: N? = 6.023 *10²³]

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alok kumar singh

Contributor-Level 10

First, the number of unit cells in the given mass is determined. In an HCP structure, there are 6 atoms and 18 total voids (6 octahedral + 12 tetrahedral) per unit cell. Multiplying the number of unit cells by 18 gives the total number of voids. The result is14.9 x 10²¹, which is rounded.

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6 months ago

Chemistry Chemistry Chemical Kinetics

A and B decompose via first order kinetics with half- lives 54.0 min and 18.0 min respectively. Starting from an equimolar non reactive mixture of A and B, the time taken for the concentration of A to become 16 times that of B is __________ min

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