KSSM CHEMISTRY FORM 4 (HALOGEN)

When descending Group 17 from fluorine to astatine,

I. the atomic size decreases

II. the melting and boiling points decrease

III. the density of the halogens increases

IV. their physical state changes from gas to liquid to solid

• I and II

• I and III

• II and IV

• III and IV

When bromine is added to sodium hydroxide and shaken, which of the following products is not formed?

• sodium bromide

• hypobromic acid

• water

• sodium hypobromite

Which of the following is a property of bromine?

• Exists as reddish-brown gas at room conditions

• Less electronegative than chlorine

• Turns moist red litmus paper blue

• Dissolves in water to form an alkaline solution

Element G, L and J are located in Group 17 of the Periodic Table. Element J is more electronegative than element G. The reaction of red-hot iron wool with gas L is more vigorous than the reaction of red-hot iron wool with gas J. The reactivity of the three elements in ascending order is

• G, J, L

• L, J, G

• L, G, J

• J, G, L

Chlorine is placed in Group 17 of the Periodic Table. Which of the following statements is not true about chlorine?

• Chlorine reacts with another element from Group 1 of the Periodic Table to form a salt

• Chlorine can bleach moist blue litmus paper

• Chlorine is more electronegative than fluorine

• Chlorine water is acidic

Element W has a proton number of 17. An ion of element R has an electron arrangement of 2.8.18.8 and a formula of R^- . It can be predicted that

• element W is less reactive than element R

• melting point of element W is higher than that of element R

• element W is denser than element R

• both the aqueous solutions of W and R can conduct electricity

Element Y is located below bromine in the Periodic Table. Which statements below is correct about Y?

I. Forms acidic oxide

II. Exists as monoatomic

III. Have seven valence electrons

IV. Dissolves in water to produce solution which bleach

colour of litmus paper

• I and III

• II and IV

• I, II and III

• I, III and IV

What is the meaning of electronegativity?

• The ability of an ion to lose electron

• The ability of an ion to gain electron

• The ability of an atom to lose electron

• The ability of atom to gain electron

Which characteristic is similar for fluorine, bromine and iodine?

• Formed coloured ions

• Exists as gas at room temperature

• Have high melting and boiling points

• Dissolve in water to form acidic solution

Astatine would form 2 acids, HAt and HOAt, when added to water. Why is the reaction very slow compared to other halogens?

• Its valence shell is the furthest away from the nucleus

• It has one valence electron in its outermost shell

• Its atomic radius is smaller than the others

• Its melting point is higher than the others