d and f BLOCK ELEMENTS MCQ Quiz: GKFix - Bridge of Knowledge - Page 117

Question 581

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What general reaction do lanthanoids undergo with dilute acids?

They form water
They liberate hydrogen gas
They absorb the acid
They become passive

Question 582

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For which application are mixed oxides of lanthanoids commonly used?

Permanent magnets
Catalysts in petroleum cracking
High-temperature superconductors
Nuclear reactor moderators

Question 583

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What is Mischmetall primarily composed of?

100% pure lanthanum
~50% lanthanoid metal and ~50% iron
~95% lanthanoid metal and ~5% iron
~95% iron and ~5% lanthanoid metal

Question 584

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What is a major industrial application of lanthanoids?

Catalysts in plastic production
Production of alloy steels
Semiconductor manufacturing
Nuclear fuel rods

Question 585

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What type of compounds are formed when lanthanoid metals are heated with carbon?

Oxides
Carbides
Sulfides
Halides