Which noble gas is used in airport runway and approach lights? 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950.

Which noble gas is used in airport runway and approach lights?

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1. He

2. Ne

3. Ar

4. Kr

5. Xe

Which of the following statements about noble gases is incorrect?

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1. Except for radon, they can be isolated by fractional distillation of air.

2. Radon can be collected from the radioactive disintegration of radium salts.

3. Helium is produced from some natural gas fields.

4. The only forces of attraction among noble gas atoms are dipole-dipole attractions.

5. The attractive forces of He are so small that it cannot be solidified at 1 atm.

Which one of the following compounds (apparently) involves sp3d2 hybridization at the xenon atom?

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1. XeO3

2. XeF2

3. XeF4

4. XeF6

5. XeO4

Which of the following equations does not represent a correct reaction?

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1. 2.

3.

4. 5.

Write and balance the formula unit equation for the reaction of iron with fluorine. The sum of the coefficients in the balanced equation (include one's) is _____.

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1. 6

2. 7

3. 3

4. 4

5. 5

Write and balance the formula unit equation for the reaction of iron with iodine. The sum of the coefficients in the balanced equation (include one's) is _____.

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1. 6

2. 7

3. 3

4. 4

5. 5

The anhydride of perchloric acid is _____.

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1. ClO2

2. Cl2O7

3. Cl2O3

4. ClO3

5. Cl2O5

Which formula is incorrect?

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1. SF4

2. SF6

3. SO2

4. SO3

5. SCl3

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1. 7.82 g

2. 12.2 g

3. 14.6 g

4. 24.4 g

5. 73.5 g

Write and balance the formula unit equation for the reaction of sulfur with potassium. Represent sulfur as S rather than S8. The sum of the coefficients in the balanced equation (include one's) is _____.

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1. six

2. seven

3. three

4. four

5. five

Which acid listed on the right cannot be obtained by adding water to the substance on the left?

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1. SO3 sulfuric acid

2. TeO2 telluric acid

3. H2S2O7 sulfuric acid

4. SO2 sulfurous acid

5. SeO2 selenous acid

Write the molecular equation for the thermal decomposition of ammonium nitrate at 170° to 260°C to produce dinitrogen oxide and steam. What is the sum of the coefficients?

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1. 4

2. 5

3. 6

4. 8

5. 9

Write the equation for the reaction of gaseous ammonia with oxygen in the presence of red-hot platinum. (This is the first step of the Ostwald process.) What is the sum of the coefficients?

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1. 17

2. 18

3. 19

4. 20

5. 21

Superphosphate of lime is produced by the reaction of phosphate rock with _____.

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1. Na2CO3

2. HCl

3. H2SO4

4. CaCO3

5. Ca(HCO2)3