PECUTAN 2 KIMIA

Determine the oxidation number of chromium, Cr in dichromate ion, Cr₂O₇^2-

• +2

• +4

• +5

• +6

A gas occupies 345 cm³ at STP. Calculate the number of moles of moles of the gas.

• 14.4

• 15.4

• 0.0154

• 0.154

What is the number of valence electrons for atom with electronic configuration of 1s² 2s² 2p⁶ 3s² 3p³

• 15

• 5

• 3

• 8

11.   Which of the following represent an element that forms ion with a charge of –2?

• 1s² 2s² 2p⁶ 3s²

• 1s² 2s² 2p⁶ 3s² 3p²

• 1s² 2s² 2p⁶ 3s² 3p⁴

• 1s² 2s² 2p⁶ 3s² 3p⁵

Orbital with quantum numbers: n=3, l=2 and m=+2 is

• 2p

• 3s

• 3f

• 3d

The electronic configuration of copper atom is

1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s¹

Determine the number of electrons in the copper atom in the ground state with the azimuthal quantum number l=0.

• 7

• 9

• 1

• 11

Which property is increasing across period 3 from left to right?

• Atomic size

• Ionisation energy

• shielding effect

• oxidation no

        Lithium and potassium belongs to the same group in Periodic Table. They have the same number of..

• proton

• valence electron

• shells

• electrons

Molecular geometry of trigonal planar will have the bond angle of..

• 109.5

• 90

• 180

• 120

Which molecules has a dipole moment, u not equal to zero?

• CCl₄

• CHCl₃

• CO₂

• CF₄