Onramps Chemistry

Consider the labeled bonds in the molecule below and rank them from least to most polar in terms of difference in electronegativity.

• d < c < a < e < b

• d < c < e < a < b

• a < b < c < d < e

• e < b < d < c < a

Tags

NGSS.HS-PS1-2

Rank the crystal lattice energy of the salts Al₂O₃, CaCl₂, CaO, NaF, Mg₃(PO₄)₂ From least to greatest:

• Mg₃(PO₄)₂ < NaF < CaCl₂ < CaO < Al₂O₃

• CaO < NaF < CaCl₂ < Al₂O₃ < Mg₃(PO₄)₂

• NaF < CaCl₂ < CaO < Mg₃(PO₄)₂ < Al₂O₃

• NaF < CaO < CaCl₂ < Mg₃(PO₄)₂ < Al₂O₃

Tags

NGSS.HS-PS1-3

Which of the following is the best representation of the compound potassium sulfide?

• 
• 
• 
• 

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Consider the methane molecule. How many LONE PAIRS of valence electrons does it have?

• 1

• 4

• 0

• 2

What kind of carbon-carbon bond is in a molecule of ethylene (C₂H₄)?

• Double

• Triple

• Single

• Ionic

Lewis structures – resonance (delocalization) Which of the following species exhibit resonance/delocalization?

I) HCN

II) O₃

III) CO₃ ^2-

• I, III

• I, II

• II, III

• II only

Octet exceptions – incomplete octet, radicals Which of the following would be radicals?

I) NO

II) NF₃

III) CN

IV) PO₄ ^3-

• II, III

• I, III

• II, III, IV

• II, IV

Draw the Lewis structure of xenon difluoride and give the number of lone pairs of electrons around the central atom.

• 2

• 5

• 4

• 3

Which of the following has bond angles slightly less than 109.5^o?

• CH₃ ⁺

• I₃ ^-

• HOCl

• O₃

Which of the following is planar?

• SO₃ ^2-

• H₃O ⁺

• NO₃ ^-

• NH₃