Hey There!
At neutralisation moles of H⁺ from HCl = moles of OH⁻ from Ca(OH)2 so :
0.204 * 42.8 / 1000 => 0.0087312 moles
Moles of Ca(OH)2 :
2 HCl + Ca(OH)2 = CaCl2 + 2 H2O
0.0087312 / 2 => 0.0043656 moles ( since each Ca(OH)2 ives 2 OH⁻ ions )
Therefore:
Molar mass Ca(OH)2 = 74.1 g/mol
mass = moles of Ca(OH)2 * molar mass
mass = 0.0043656 * 74.1
mass = 0.32 g of Ca(OH)2
Hope that helps!
Formula of isocyanic acid is HNCO. It colourless, volatile compound. It is poisonous inorganic compound. Melamine is synthesized from urea. The reaction involves two steps. In first step, urea gets converted to isocyanic acid which is an intermediate. In the second step, isocyanic acid gives melamine (molecular formula C₃H₆N₆) and carbon dioxide (CO₂). The balanced chemical reaction involved in second step is given below:
6 HNCO → 1 C₃N₃(NH₂)₃ + 3CO₂
The co-efficient of the reaction are: 6, 1, 3
Answer: C) To monitor weather event restricted several days in advance.
Explanation: