Class 12th
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New answer posted
4 months agoContributor-Level 10
Haematite: Fe? O?
Bauxite: Al? O? ·xH? O
Magnetite: Fe? O?
Malachite: CuCO? ·Cu (OH)?
New answer posted
4 months agoContributor-Level 9
Matching Calcium Compounds to their Description:
o Ca (OCl)? : Bleach
o CaSO? • ½ H? O: Plaster of paris
o CaO: Component of cement
o CaCO? : Antacid
New answer posted
4 months agoContributor-Level 9
Reaction Sequence:
o NO? + CH? COOH → HNO? + CH? COO?
o Sulphanilic acid (+ NH? CH? COO? ) + HNO? → N-acetylated diazonium intermediate + 2H? O
The intermediate + another molecule → Red Azodye + NH? + CH? COOH
New answer posted
4 months agoContributor-Level 10
Unimolecular Reactions might seem to not participate in the collision theory due to the presence of only a single molecule. In such cases, the molecule is activated by external forces such as heat, light, electricity, or by colliding with the walls of the container. This force charges the molecule enough to break the activation barrier and result in an effective collision.
New answer posted
4 months agoContributor-Level 9
Potential difference across resistor at time t = V = 30/3 = 10V
Current, I = 10 / (5 * 10? ) = 2? A
New answer posted
4 months agoContributor-Level 10
100 mol of KBr is doped with 10? mol of SrBr?
Therefore, 1 mol of KBr contains 10? mol of SrBr?
Molar mass of KBr = 119 g/mol .
119 g of KBr contains 10? mol of SrBr?
1 g of KBr contains (10? / 119) mol of SrBr?
Each Sr²? ion introduced creates one cation vacancy to maintain electrical neutrality.
Number of cation vacancies = (moles of SrBr? ) * (Avogadro's number)
Number of vacancies = (10? / 119) * (6.023 * 10²³) = 5.06 * 10¹?
The answer provided in the document is "5 (Rounded off)", which likely refers to the coefficient 5.06.
New answer posted
4 months agoContributor-Level 10
The reaction is N? O? (g)? 2NO? (g).
Δn_g = (moles of gaseous products) - (moles of gaseous reactants) = 2 - 1 = 1.
The relationship between Kp and Kc is Kp = Kc (RT)^Δn_g.
600.1 = 20.4 * (0.0831 * T)¹
T = 600.1 / (20.4 * 0.0831) = 353.99 K.
The answer, rounded off, is 354 K.
New answer posted
4 months agoContributor-Level 10
Using the Ideal Gas Law, PV = nRT:
P = 1 bar
V = 20 mL = 0.020 L
R = 0.083 L·bar·mol? ¹·K? ¹
T = 273 K
n = PV / RT = (1 * 0.020) / (0.0831 * 273) = 8.8 * 10? mol of Cl?
Number of Cl? molecules (N) = n * N_A = (8.8 * 10? ) * (6.022 * 10²³) = 5.3 * 10²? molecules.
Number of Cl atoms = 2 * (5.3 * 10²? ) = 1.06 * 10²¹.
The answer, rounded off to the nearest integer for the power of 10²¹, is 1.
New answer posted
4 months agoContributor-Level 10
For the dissociation of K? [Fe (CN)? ]? 4K? + [Fe (CN)? ]? , the number of ions produced (n) is 5.
The degree of dissociation (α) is related to the van't Hoff factor (i) by α = (i-1)/ (n-1).
Given α = 0.4: 0.4 = (i - 1) / (5 - 1) => 1.6 = I - 1 => I = 2.6
Using the depression in freezing point formula (ΔTf = i·Kf·m), and equating the ΔTf for two different solutions:
ΔTf (K? [Fe (CN)? ]) = ΔTf (A)
i? ·Kf·m? = i? ·Kf·m?
(2.6) * [ (18.1 / M) / (100-18.1)/1000] = (1) * [ (w? /M? ) / (W? /1000)]
The problem simplifies to finding the molar mass M of solute A:
2.6 * [18.1 / (M * 81.9)] * 1000 = [w? /M? ] * [1000/W? ]
Assuming the secon
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