A student says that since the atomic theory is just a theory, it should not be considered useful. Which statement best argues against the student's opinion? (2 points)
O Scientific theories change over time.
O Scientists often do not agree about specific details of scientific theories.
O Scientists often propose competing theories.
O Scientific theories do not become Scientific Laws.
O Scientific theories are the results of many experiments and observations.

O Scientific theories are the results of many experiments and observations.

Explanation:

Going through the options;

O Scientific theories change over time.

This is true and supports the student's opinion. So wrong option!

O Scientists often do not agree about specific details of scientific theories.

This is true. However, it supports the student's opinion. So wrong option!

O Scientists often propose competing theories.

This is true. However, it supports the student's opinion. So wrong option!

O Scientific theories do not become Scientific Laws.

This is False. Theories that have withstood the test of time and countless experiments become laws. However it support's the student's opinion. So wrong option!

O Scientific theories are the results of many experiments and observations.

This is true and is against the student's opinion. This option is correct!

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