Tourmalene is a class of cyclosilicates with general formula. `(Ca, K, Na) (Al, Fe, Li, Mg, Mn)_(3)(Al, Cr, Fe, V)_(6) (BO_(3))_(3) (Si, Al, B)_(6)O_(18)(OH, F)_(4)` Which of the following is not a correct example of tourmalene ?A. `CaAl_(3)Fe_(6)(BO_(3))_(3)S_(6)O_(18)F_(4)`B. `Ca_(2)Li_(3)V_(6)(BO_(3))_(3)Si_(6)O_(18)(OH)_(4)`C. `KMg_(3)Cr_(6)(BO_(3))_(3)Si_(6)O_(18)F_(4)`D. `CaAl_(9)(BO_(3)_(3)Si_(6)O_(18)(OH)_(4)`

Tourmalene is a class of cyclosilicates with general formula. `(Ca, K,

1.	Tourmalene is a class of cyclosilicates with general formula. `(Ca, K, Na) (Al, Fe, Li, Mg, Mn)_(3)(Al, Cr, Fe, V)_(6) (BO_(3))_(3) (Si, Al, B)_(6)O_(18)(OH, F)_(4)` Which of the following is not a correct example of tourmalene ?A. `CaAl_(3)Fe_(6)(BO_(3))_(3)S_(6)O_(18)F_(4)`B. `Ca_(2)Li_(3)V_(6)(BO_(3))_(3)Si_(6)O_(18)(OH)_(4)`C. `KMg_(3)Cr_(6)(BO_(3))_(3)Si_(6)O_(18)F_(4)`D. `CaAl_(9)(BO_(3)_(3)Si_(6)O_(18)(OH)_(4)`
Answer» Correct Answer - A You are not expected to have a prior knowledge of tournaline.It is simply a common-sense based question based on adding all the changes. `(1)+2+3xx3+x xx 6-3xx3+4xx6-2xx18-1xx4` `=6 xx -14 ne 0` for `x=+2` or `+3` (possible on Fe) `(2)+2xx2+1xx3+3xx6-3xx3+6xx4-18xx2-1xx4=0` it fits so it is possible `(3)+1xx1+2xx3+3xx6-3xx3+4xx6-2xx18-1xx4=0` `(4)+2xx1+9xx3-3xx3+6xx4-2xx18-1xx4=0`

vii. The stability of dihalides of ` Si, Ge , Sn` and Pb increases steadily in the sequence :A. `GeX_(2) lt SiX_(2) lt SnX_(2) lt PbX_(2)`B. `SiX_(2) lt GeX_(2) lt PbX_(2) lt SnX_(2)`C. `SiX_(2) lt GeX_(2) lt SnX_(2) lt PbX_(2)`D. `PbX_(2) lt SnX_(2) lt GeX_(2) lt SiX_(2)`
When `H_2S` is passed through acidified `KMNO_4`, we getA. `K_(2)SO_(4)`B. `MnO_(2)`C. `KHSO_(3)`D. Sulphur
The`3ClO^(-)(aq.)to ClO_(3)^(-)(aq.)+2Cl^(-)(aq.)` is an example ofA. oxidation reactionB. disproportionationC. reduction reactionD. decomposition
The reaction: `ClO_(3)^(-) +I_(2) to IO_(3)^(-)+Cl_(2)`A. is possibleB. depends upon the state of productsC. is not possibleD. depends upon the temperature
In the reaction: `3Br_(2)+6OH^(Theta)rarr 5Br^(Theta)+BrO_(3)^(Theta)+3H_(2)O,Br_(2)` isA. is reducedB. is oxidizedC. disproportionatesD. disintegrate
`NaClO_(3)` is obtained by reacting `Cl_(2)` andA. cold dil. NaOHB. hot conc. NaOHC. cold `Na_(2)O_(2)`D. hot `Na_(2)O_(2)`
Which of the following is acidic oxides ?A. `HClSO_(4)`B. `MgO`C. `Al_(2)O_(3)`D. `CaO`
Which of the following is more acidic oxyacid ?A. `HClO_(4)`B. `HClO`C. `HClO_(3)`D. `HClO_(2)`
Oxygen orm acidic oxide withA. CaB. NaC. SD. K
Of the following, the most acidic isA. `As_(2)O_(3)`B. `P_(2)O_(3)`C. `Sb_(2)O_(3)`D. `Bl_(2)O_(3)`