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Alkali metal halides have high negative ...

Alkali metal halides have high negative enthalpies of formation. The `Delta_(f)H^(@)` values for _____ become less negative as we go down the group.

A

iodides

B

bromides

C

chlorides

D

fluorides

Text Solution

Verified by Experts

The correct Answer is:
D
`LiF(-612 "kJ mol"^(-1)), NaF(-569), KF(-563),RbF (-549), "and" CsF (-531)`, whilst the reverse is true for `Delta_(f)H^(@)` for chlorides, bromides, and iodides. This is due to the fact that `F^(-)` is relatively small in size and, thus, is best stabilized by smaller cations while other halide ions are relatively bigger and are stabilized by bigger cations.
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R SHARMA-THE S BLOCK ELEMENTS-Follow-up Test 4
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  2. On combustion in excess ofd air, lithium forms

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  3. Which of the following in incorrect for the hydroxides of alkali metal...

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  6. The alkali metal halides (MX) are all high melting, colorless crystall...

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  7. Alkali metal halides have high negative enthalpies of formation. The D...

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  8. The magnitude of enthalphy of formation of alkali metal halides decrea...

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  9. Which of the following is soluble in organic solvents like ethanol ?

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  10. Which of the following has the maximum melting point but minimum solub...

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  11. Which of the following is the correct order of hyrated ionic radii ?

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  12. Which of the following compounds is almost insoluble in water ?

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  13. The melting and boiling points of alkali metal halides always follow t...

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  14. Which of the following are oxosalts ? (i) Carbonates , (ii) Nitrates...

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  15. Which of the following is nott true?

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  16. Which of the following alkali metal carbonates doesnot existin the sol...

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  17. Sodium bicarbonate (NaHCO(3)) on gentle heting produces

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  18. Which of the following has the maximum solubility in water?

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