Answer!! 50 points Which statement describes the properties of lanthanoids and actinoids?(1 point)

A. They are malleable and lustrous, and they tend to conduct both electricity and thermal energy.

B. They are brittle and dull, and they tend to conduct both electricity and thermal energy.

C. They are brittle and dull, and they tend to be poor conductors of both electricity and thermal energy.

D. They are malleable and lustrous, and they tend to be poor conductors of both electricity and thermal energy.

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

brian made this table to organize his notes on changes of state. depostion is a change of state that has the wrong energy change listed. it is utilized to collect data as a portion of the development means and in restricted conditions which may be applied at test.

a deposition in the authority of the united states or research for development in the authority of canada includes the catching of affirmed. the out-of-court verbal assertion of a spectator that may be lessened to a printed record for succeeding application for discovery purposes.