Which of the following halogens is found in a monoatomic form in nature?

• None of them

• Bromide      

• Chlorine

• Fluorine      

• Iodine

Which are not correct for chlorine?

• Used as a fertilizer

• Found in salt beds and seawater as its salts

• Used in the production of insecticides

• Used in the manufacture of plastics

• Produced by electrolysis

Which of the following are not a property of halogens?

• They form acids with hydrogen

• They are good conductors of heat

• They are found in diatomic molecules in nature

• They form salts with metals

• They are nonmetals

How many grams and moles of Cl₂ are needed to form 27,5 g of PC1₃

• 21,3 g; 0,25 mol

• 42,6 g

• 7,1     g

• 0,025 mol

• 0,0025 mol

Which of the following compounds have not yet been synthesized?

• NeO₂; NeHO₂   

• XeO₃; NeHO₂   

• XeF₂; RnCl₄

• NeO₂; KrF₃

• RnCl₄; XeF₂

The oxidation state of chlorine in compounds: Ca(OCl)₂, HClO₃ :

• + 1; + 5

• – 1; + 1

• + 3; + 5

• + 1; +2

• +2; – 2

Hydrogen bromide can react with:

• Ethanol; Ethylene glycol; Glycerin

• Phenol; Ethanol; Ethylene glycol

• Ethanol; Water; Hydrogen peroxide; Water

• Ethylene glycol; Hydrogen peroxide; Hydrogen peroxide

• Ethanol; Ethylene glycol; Stearic acid

Which elements are not a 17A group?

• P; Mn;  N

• H; Mn; N

• Br;     I; P

• I; P; At        

• P; At; Cl

Which of the following are not the oxidation state of chlorine?

• +2; -2; -7

• +l; -1; +5

• -1; +3

• +1; +3; +7

• +5; -1; +3

Which one of the following is not correct for catalysts?

• They are usually active metals

• They decrease activation energy

• They remain unchanged after the reaction

• Enzymes are catalysts

• They increase reaction rate