PLEASE HELP CHEMISTRY DIMENSIONAL ANALYSIS DUE IN 5 MINUTES

37.6 Km/h

Explanation:

From the question given above, the following data were obtained:

Distance = 100 m

Time = 9.58 s

Speed =?

Next, we shall convert 100 m to Km. This can be obtained as follow:

1000 m = 1 Km

Therefore,

100 m = 100 m × 1 Km / 1000 m

100 m = 0.1 km

Next, we shall convert 9.58 s to h. This can be obtained as follow:

3600 s = 1 h

Therefore,

9.58 s = 9.58 s × 1 h / 3600 s

9.58 s = 2.66×10¯³ h

Finally, we shall determine the speed. This can be obtained as follow:

Distance = 0.1 km

Time = 2.66×10¯³ h

Speed =?

Speed = Distance / Time

Speed = 0.1 / 2.66×10¯³

Speed = 37.6 Km/h

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