Diagonal Relationship between Beryllium and Aluminium The ionic radius of Beryllium (Be 2+) is estimated to be nearly 31 pm; the charge/radius ratio Or e/m ratio is nearly the same as that of the Al 3+ ion. Hence beryllium resembles aluminium in these ways. Some of the similarities are given below: » Like Aluminium, Beryllium(be) is not readily attacked by acids H+ donor because of the formation of an oxide film on the surface of the metal by reacting with oxygen, i.e. they are rendered passive by nitric acid. » Beryllium hydroxide[[Be(OH)4]2] dissolves in excess of alkali to give a beryllate ion, [ Be(OH)4]2– just as aluminium hydroxide[Al(OH)3] gives aluminate ion, [Al(OH)4] » The chlorides of metals beryllium and aluminium have Cl– bridged chloride structure in vapour phase. Both the chlorides are soluble in organic solvents and are strong as Lewis acids They are used as Friedel Craft catalysts. » Beryllium(Be) and aluminium(Al) ions have strong tendency to form complexes, (Be...
SECTION-A 1. When reading a file line by line, the exact contents can be printed by: (A) Using readline ( ) (B) Using readlines ( ) (C) Using ‘,’ after every print statement (D) Both (A) & (B) 2. Choose the correct Python expression for the following mathematical expressions p+q/(r+s)4 (A) p+q / math.pow ((r+s), 4) (B) p+q/(r+s)^4 (C) p+q / math.pow (r+s,4) (D) (p+q) / math.pow (r+s) 3. Identify the correct statement for opening text file data.txt in total folder of c:drive in read mode. (A) F = open (“c:\\total\\data.txt”, “r”) (B) F = open (“c:\total\data.txt”, r) (C) F = open (“c:\total\data.txt”) (D) F = open (“\total\data.txt”, “r”) 4. A valid combination of atoms and operators forms a Python (A) Statement (B) Expression (C) Condition (D) None of these. 5. The default file open mode in Python is (A) Write (B) Read (C) Append (D) Read/write 6. In Python, a block is executed in an .................... (A) Function (B) Module (C) Py file (D) Execution frame 7. Consider ...
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Ques : Phosphorus and chlorine form two compounds The first compound contains 22.54% by mass of phosphorus and 77.46% by mass of chlorine. In the second compound the percentages are 14.88 for phosphorus and 85.12 for chlorine. Show that these data are consistent with the law of multiple proportions. Ans : In the first compound, Percentage of phosphorus = 22.54 Percentage of chlorine = 77.46 Thus, 22.54 g of phosphorus combines with 77.46 g chlorine. In the second compound, Percentage of phosphorus = 14.88 Percentage of chlorine = 85.12 Thus, 14.88 g of phosphorus combine with 85.12 g of chlorine. Let us fix the mass of phosphorus as 1 g and find the different masses of chlorine which combine with 1 g of phosphorus in two compounds. In the first compound, Mass of chlorine which combines with 22.54 g of phosphorus = 77.46 g The mass of chlorin...
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