W Nitro Type Prone Hunger Games
Other bookmarks
Two substances have the same temperature. The particles of Substance A1 point
have a slower average speed than the particles in Substance B. What can
you say about the molar masses of the two substances?
O Their molar masses are the same.
The molar mass of Substance A is greater than Substance B
B the molar mass of substance is greater than substance b
C The molar mass of substance B is greater than substance a
D there is not enough information

C The molar mass of substance B is greater than substance A

Explanation:

From the description given, the molar mass of substance B is definitely greater than that of substance A.

 Temperature increases the kinetic energy of a body. The average molecular speed increases with increasing temperature.

 Since the two bodies given are at the same temperature, the one having a lesser molecular mass will have a higher speed.

Substances with low molecular mass can diffuse or effuse more rapidly than one with higher molecular mass under similar conditions.

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

it's c (engineer's do their work with mechanical stuff not on any living being)