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CHAP 7/5
Question | Answer |
---|---|
STRENGTH OF HALIDE AS REDUCING AGENTS INCREASE FROM ... | CL- TO I-. 2X- +2E-àX2. |
WHY ARE CHLORINE IONS VERY DIFFICULT TO OXIDES ... | COZ WEAK REDUCING AGENTS HARDER TO LOSE ELECTRON. OXIDISED BY KMAGANATE OR CLO- IONS IN DILUTE SULPHURIC ACID. |
IS IT EASY TO OXIDISED A BR ION ...? | YES , BROMIDE IONS MORE EASILY OXIXDISED BY, BY CL-, KDICHROMATE (VI) & KMAGANATE IN DILUTE SULPHURIC ACID. |
IODIDE IONS STRONG REDUCING AGENTS SO ARE... | OXIDISED BY MANY. E.G. FE2+ REDUCED TO FE3+ IODINE IONS IN SOLUTION. 2 HALF EQUATIONS ARE: 2I-(AQ) àI2(S) +2E- , FE3+(AQ) + E- à FE2+(AQ). |
BECAUSE KBROMIDE IS COLOURLESS THE EQUATIONS ARE ... | KBR +H2SO4 à HBR +KHSO4. 2HBR +H2SO4 àBR2 + SO2 +2H2O. |
WHEN IODIDE PRODICED WHAT COLOUR FUMES... | STEAMY FUMES OF IODIDE BUT MOSTLY VIOLET CLOUD OF IODINE VAPOUR & YELLOW SULPHUR. SMELL OF ROTTEN EGGS COZ HYDROGEN SULFIDE ALSO PRODUCED. |
WHAT MAKES SMELL OF ROTTEN EGGS .. | HYDROGEN SULFIDE. |
TEST FOR HALIDES ... | DILUTE NITRIC ACID IS ADDED TO SOLUTION OF UNKNOWN HALIDE UNTIL JUST ACIDIC. AG NITRATE SOLUTION ADDED. CL-,BR-,I- ALL PRODUCE A PRECIPITATE OF SILVER HALIDE. |
WHAT COLOUR PRECIPITATE DOES HALIDES GIVE IN TEST ... | CHLORIDE (INCLUDING HCL) GIVE A WHITE PRECIPITATE |
SOLUBLE IN DILUTE AQUEOUS AMMONIA. BROMIDES GIVE CREAM PRECIPITATE WHICH IS INSOLUBLE IN DILUTE AQUEOUS AMMONIA BUT SOLUBLE IN CONCENTRATED AQUEOUS AMMONIA. | |
IODIDES GIVE PALE YELLOW PRECIPITATE | INSOLUBLE IN BOTH DILUTE AND CONCENTRATED AQUEOUS AMMONIA. |
WHY IS DILUTE NITRIC ACID ADDED TO SILVER HALIDE PRECIPITATE... | TO PREVENT THE PRECIPITATION OF OTHER IONS (CARBONATE) BY SILVER IONS. |
WHEN A MIXTURE OF H2 AN O2 IN A 2:1 RATIO IS IGNITED WITH A SPARK .... | WATER IS PRODUCED AND NO UNCOMBINED HYDROGEN OR OXYGEN IS LEFT |
NO UNCOMBINED HYDROGEN OR OXYGEN IS LEFT (THIS IS AN EXAMPLE OF .... | A COMPLETE AND IRREVERSIBLE REACTION) .2H2(G) +O2(G) à2H2O(L). |
DO ALL REACTIONS REACT COMPLETELY ... | NO. |
MIXTURE OF HYDROGEN AND IODINE IN RATIO 1:1 HEATED TO 300 DEGREES HOW MUCH REACT ... | ONLY 90% REACT. H2(G)+ I2(G) REVERSIBLE ARROW 2HI(G). |
A REVERSIBLE REACTION IS ONE THAT ... | GOES IN BOTHER DIRECTIONS AT THE SAME TEMPERATURE. |
AT 300 DEGREES, OF REACTION OF H2 AND I2.... | 10% WILL ALWAYS BE LEFT. |
WHEN THERE IS NO FURTHER CHANGE IN AMOUNTS OF REACTANT AND PRODUCTS THE SYSTEM IS SAID... | TO BE IN EQUILIBRIUM. |
IF SYSTEM REACHES EQUILIBRIUM THERE IS NO ... | FURTHER CHANGE IN THE CONCENTRATIONS OF REACTANTS AND PRODUCTS. |
AS TIME PASSES THE CONC OF H2 AND I2 BECOME ... | LOWER SO THE RATE OF REACTION DECREASES. |
SOON AS REACTION OF H + I2 STARTS SOME ... | SOME HI FORMED BEGINS TO DECOMPOSE TO HYDROGEN AND IODINE. |
WHY AT FIRST IS REACTION IS SLOW ... | COZ CONC OF HI SMALL, AS TIME PASSES THE RATE OF THE REVERSE REACTION INCREASE UNTIL BOTH FORWARD AND REVERSE ARE EQUAL AFTER THIS THERE IS NO CHANGE IN CONCENTRATION . |
.BOTH FORWARD AND REVERSE ARE EQUAL AFTER THIS THERE IS NO CHANGE IN CONCENTRATION IS CALLED... | THE SYSTEM IS IN EQUILIBRIUM |
WITH THE FORWARD AND REVERSE REACTION TAKING PLACE AT THE SAME TIME THIS IS ... | CALLED DYNAMIC EQUILIBRIUM. |
H2+I2 à2HI EQUALS THE RATE OF THE 2HI àH2+I2. | |
DYNAMIC EQUILIBRIUM IS WHEN ... | THE RATE OF THE FORWARDS AND REVERSE REACTION ARE EQUAL THUS THERE IS NO FURTHER CHANGE IN THE CONCENTRATIONS OF THE REACTANTS AND PRODUCTS. |
DO REACTIONS STOP WHEN EQUILIBRIUM REACHED... | NO |
REACTION DON’T STOP WHEN EQUILIBRIUM REACHED CAN BE PROVED USING... | RADIOACTIVE TRACERS,HI CONTAINING A TRACE OF RADIOACTIVE I-131 IS MIXED WITH I2 AND H2 IN EQUILIBRIUM PROPORTIONS AT 300 DEGREES AND LEFT FOR SEVERAL MINUTES. |