1) Which type of bond involves valence electrons constantly moving between atoms, like a sea of electrons? a. Ionic
b. Covalent
c. Molecular
d. Metallic
(if you answer this i will give you brainliest) ---
2) An atom of Nickel (Ni) has bonded to another atom to form a solid, crystal-like substance with a high boiling point. Which atom has Ni most likely bonded with?

a. Ca
b. Fe
c. S
d. Li

d. Metallic

c. S

Explanation:

A metallic bond is an interatomic bond in which valence electrons are constantly moving between atoms like a sea of electrons.

2. The bond type described in the second problem is an ionic bond. This results in the formation of crystal lattice with strong bonds.

i believe it is c.) 1575 j.

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