Page 125 - Chemistry eBook

HH
How many pairs of electrons are shared between the two nitrogen atoms?
(1) 1 (3) 3
Sample Regents Questions
(2) 2 (4) 4
38 Which formulas represent one ionic compound and one molecular compound?
(1) N2 and SO2 (3) BaCl2 and N2O4 (2) Cl2 and H2S (4) NaOH and BaSO4
39 Which Kelvin temperature is equal to 200.°C?
(1)􏰁73K June2013(3#)32800.K (2) 73 K (4) 473 K
40 A 10.0-gram sample of H2O(l) at 23.0°C absorbs 209 joules oAfnshweeart. What is the final
temperature of the H2O(l) sample? (1) 5.0°C (3) 28.0°C
43 Which hydroca
H HC
H (
H H C
(
Choice #3
Explanation:
• We know that ionic bonds form between a metal and a nonmetal and covalent bonds (molecular compound) form
(2) 18.0°C (4) 50.0°C
between two metals. N and O are both nonmetals, so the bond between them is covalent.
• Ba is a metal and Cl is a nonmetal, so the bond between them is ionic.
• Youcanalsofindthisanswerbyfindingthedifferencebetweentheelectronegativities( Reffy,TableS).
41 Given the equation representing a system at
• If the difference is greater than 1.7, the compound is ionic. If the difference is less than 1.7, the compound is
covalent (moleceulqaru).ilibrium: BaCl2:
H O N2O4: 2 N=3
Ba=0.9
Cl=3.2
3.2−0.9 = 2.3.
This is an ionic compound (greater than 1.7). 3.4−3 = 0.4.
􏰂􏰂􏰂􏰂⇀
AgCl(s) ↽􏰂􏰂􏰂􏰂 Ag􏰀(aq) 􏰀 Cl􏰁(aq)
O=3.4
This is a molecular/covalent compound (less than 1.7).
When the concentration of Cl􏰁(aq) is increased, the concentration of Ag􏰀(aq)
( 1)
( 2)
formula rbon?
H CH H
1)
CH
H 2)
UNIT 4: BONDING © 125
(1) decreases, and the amount of AgCl(s)
r