Smoke screen is a mass of dense artificial smoke used to conceal military areas or operations from an enemy.It is produced by calcium phosphide \(Ca _3 P _2+6 H _2 O \rightarrow 3 Ca ( OH )_2+2 PH _3\) Phosphene \(\left( PH _3\right)\) so formed spontaneously catches fire to give \(P _2 O _5\) \(2 PH _3+4 O _2 \rightarrow P _2 O _5+3 H _2 O\) \(P _2 O _5\) forms a white dense smoke screen.
11. THE P-BLOCK ELEMENTS
189720
Sodium oxalate on heating with conc. \({H_2}S{O_4}\) gives
1 \(CO\) only
2 \(C{O_2}\) only
3 \(CO\) and \(C{O_2}\)
4 \(S{O_2}\) and \(S{O_3}\)
Explanation:
(c) Sodium oxalate react with conc. \({H_2}S{O_4}\) to form \(CO\) and \(C{O_2}\) gas.
11. THE P-BLOCK ELEMENTS
189721
Extraction of lead by reduction methods is done by
1 Adding more galena into reverberatory furnace
2 Adding more lead sulphate into reverberatory furnace
3 Adding more galena and coke into the reverberatory furnace
4 Self reduction of oxide from sulphide present in the furnace
Explanation:
Lead is a chemical element with atomic number \(82\) and symbol \(Pb\). Lead is easily extracted from its ores. A principal ore of lead, galena(lead sulfide \(PbS\) ).
Smoke screen is a mass of dense artificial smoke used to conceal military areas or operations from an enemy.It is produced by calcium phosphide \(Ca _3 P _2+6 H _2 O \rightarrow 3 Ca ( OH )_2+2 PH _3\) Phosphene \(\left( PH _3\right)\) so formed spontaneously catches fire to give \(P _2 O _5\) \(2 PH _3+4 O _2 \rightarrow P _2 O _5+3 H _2 O\) \(P _2 O _5\) forms a white dense smoke screen.
11. THE P-BLOCK ELEMENTS
189720
Sodium oxalate on heating with conc. \({H_2}S{O_4}\) gives
1 \(CO\) only
2 \(C{O_2}\) only
3 \(CO\) and \(C{O_2}\)
4 \(S{O_2}\) and \(S{O_3}\)
Explanation:
(c) Sodium oxalate react with conc. \({H_2}S{O_4}\) to form \(CO\) and \(C{O_2}\) gas.
11. THE P-BLOCK ELEMENTS
189721
Extraction of lead by reduction methods is done by
1 Adding more galena into reverberatory furnace
2 Adding more lead sulphate into reverberatory furnace
3 Adding more galena and coke into the reverberatory furnace
4 Self reduction of oxide from sulphide present in the furnace
Explanation:
Lead is a chemical element with atomic number \(82\) and symbol \(Pb\). Lead is easily extracted from its ores. A principal ore of lead, galena(lead sulfide \(PbS\) ).
Smoke screen is a mass of dense artificial smoke used to conceal military areas or operations from an enemy.It is produced by calcium phosphide \(Ca _3 P _2+6 H _2 O \rightarrow 3 Ca ( OH )_2+2 PH _3\) Phosphene \(\left( PH _3\right)\) so formed spontaneously catches fire to give \(P _2 O _5\) \(2 PH _3+4 O _2 \rightarrow P _2 O _5+3 H _2 O\) \(P _2 O _5\) forms a white dense smoke screen.
11. THE P-BLOCK ELEMENTS
189720
Sodium oxalate on heating with conc. \({H_2}S{O_4}\) gives
1 \(CO\) only
2 \(C{O_2}\) only
3 \(CO\) and \(C{O_2}\)
4 \(S{O_2}\) and \(S{O_3}\)
Explanation:
(c) Sodium oxalate react with conc. \({H_2}S{O_4}\) to form \(CO\) and \(C{O_2}\) gas.
11. THE P-BLOCK ELEMENTS
189721
Extraction of lead by reduction methods is done by
1 Adding more galena into reverberatory furnace
2 Adding more lead sulphate into reverberatory furnace
3 Adding more galena and coke into the reverberatory furnace
4 Self reduction of oxide from sulphide present in the furnace
Explanation:
Lead is a chemical element with atomic number \(82\) and symbol \(Pb\). Lead is easily extracted from its ores. A principal ore of lead, galena(lead sulfide \(PbS\) ).
Smoke screen is a mass of dense artificial smoke used to conceal military areas or operations from an enemy.It is produced by calcium phosphide \(Ca _3 P _2+6 H _2 O \rightarrow 3 Ca ( OH )_2+2 PH _3\) Phosphene \(\left( PH _3\right)\) so formed spontaneously catches fire to give \(P _2 O _5\) \(2 PH _3+4 O _2 \rightarrow P _2 O _5+3 H _2 O\) \(P _2 O _5\) forms a white dense smoke screen.
11. THE P-BLOCK ELEMENTS
189720
Sodium oxalate on heating with conc. \({H_2}S{O_4}\) gives
1 \(CO\) only
2 \(C{O_2}\) only
3 \(CO\) and \(C{O_2}\)
4 \(S{O_2}\) and \(S{O_3}\)
Explanation:
(c) Sodium oxalate react with conc. \({H_2}S{O_4}\) to form \(CO\) and \(C{O_2}\) gas.
11. THE P-BLOCK ELEMENTS
189721
Extraction of lead by reduction methods is done by
1 Adding more galena into reverberatory furnace
2 Adding more lead sulphate into reverberatory furnace
3 Adding more galena and coke into the reverberatory furnace
4 Self reduction of oxide from sulphide present in the furnace
Explanation:
Lead is a chemical element with atomic number \(82\) and symbol \(Pb\). Lead is easily extracted from its ores. A principal ore of lead, galena(lead sulfide \(PbS\) ).
