CH 5
CH 6
CH 7
200
How many nitrate formula units are in 4.9 mol Ca(NO3)2?
5.9 x 1024 NO3 formula units
200
How many valence electrons does a sulfur ion have?
8
200
Which compound has a lower surface tension: CO2 or CH2O?
CO2
400
Oxalic acid has an empirical formula of CHO2. If its molar mass is 90.034 gmol-1, what is its molecular formula?
C2H2O4
400
Determine the e– geometry, molecular geometry, & bond angle of ozone (O3). If possible, draw any resonance structures of O3 as well.
E– geometry = trigonal planar; Molecular geometry = bent; Bond angle = 120°; Resonance structures:
400
How much heat (in kJ) is needed for 2.50 moles of water to go from –5°C to 105°C? (The specific heat capacity of water is 4.184 J/g°C.)
q = 21 kJ
600
What is the empirical formula of a salt composed of 17.6% sodium, 39.7% chromium, & 42.8% oxygen?
Cr2Na2O7
600
Rank the following in order from weakest to strongest IMF (including ionic bonding): CH4, CH2O, FeCl2, H2O, & CO2
(weakest) CH4, CO2, CH2O, H2O, FeCl2 (strongest)
600
John puts 250. g of water @room temp (25°C) on the stove to make coffee. How much heat is needed for the water to boil, so he can make his coffee? (ΔHfus water = 6.01 kJ/mol; ΔHvap water = 40.68 kJ/mol.)
q = 611 kJ