The dotted line between 0- and H+ represents a
-0)
A)
covalent bond between the two oppositely charged ions.
B)
o
hydrogen bond, a weak bond between a hydrogen and an electronegative
atom.
strong, short-distance bond that is responsible for the unique properties of
water.
polar covalent bond that results from the unequal and opposite charges of
the ions.
D)

hydrogen bond, a weak bond between a hydrogen and an electronegative

atom.

Explanation:

Hydrogen bonding, is an intermolecular or intramolecular interaction involving a hydrogen atom located between a pair of other atoms having a high affinity for electrons; such a bond is weaker than an ionic bond or covalent bond but stronger than van der Waals forces. Hydrogen bonds can exist between atoms in different molecules or in parts of the same molecule.

A hydrogen bond is a type of dipole-dipole interaction; it is not a true chemical bond. These attractions can occur between molecules (intermolecularly) or within different parts of a single molecule (intramolecularly) as explained above.

Oxygen is strongly electronegative. Hydrogen bonds are observed when hydrogen is bonded to strongly electronegative species such as oxygen. Hydrogen bonds account for the high boiling point of water.

when 25.0 ml of 0.700 mol/l naoh was mixed in a calorimeter with 25.0 ml of 0.700 mol/l hcl, both initially at 20.0 °c, the temperature increased to 22.1 °c. the heat capacity of the calorimeter is 279 j/°c.

the equation for the reaction is:

naoh + hcl → nacl + h₂o

moles of hcl = 0.0250 l hcl ×

0.700

mol hcl

1 l hcl = 0.0175 mol hcl

volume of solution = (25.0 + 25.0) ml = 50.0 ml

mass of solution = 50.0 ml soln ×

1.00

ml soln

= 50.0 g soln

δt=t2-t1

= (22.1 – 20.0) °c = 2.1 °c

the heats involved are

heat from neutralization + heat to warm solution + heat to warm calorimeter = 0

q1+q2+q3=0

nδh+mcδt+cδt=0

0.0175 mol ×

δh

+ 50.0 g × 4.184 j·g⁻¹°c⁻¹ × 2.1 °c + 279 j°c⁻¹ × 2.1 °c = 0

0.0175 mol ×

δh

+ 439.32 j + 585.9 j = 0

0.0175 mol ×

δh

= -1025.22 j

δh=1025.22j0.0175 mol= -58 600 j/mol = -58.6 kj/mol