Volume is equal to Mass/Density so therefore, you do the mass which is 68.0 g/0.72 g/mL which is the density and get 94.44 mL because the g cancel each other out when it comes to the label!

3 0

2 years ago

Pure chlorobenzene (C6H5Cl) has a normal boiling point of 131.00 °C. A solution of 32.5 g of 2,8-dibromodibenzofuran (C12H6Br2O)

vichka [17]

Answer:

Kb → 1.56 °C / m

Explanation:

This is all about boiling point elevation, the colligative property that shows that boiling point for a solution is higher than boiling point of pure solvent.

This is the formula: ΔT = Kb . m . i

where i is the Van't Hoff factor (ions dissolved in solution). As these are organic compounds, we assume they are non electrolytic,

m is molality (mol of solute / 1kg of solvent)

Kb is our unknown. The value for ebulloscopic constant, it is specific for each solvent.

ΔT = T° boiling from solution - T° boiling from solute

First of all, let's determine the moles of solute.

Mass / Molar mass → 32.5 g/ 113.45 g/mol = 0.286 mol

Molality is mol of solute/ 1 kg of solvent

We must convert the mass from g to kg

195g . 1kg /1000 = 0.195 kg

Molality = 0.286 mol / 0.195 kg = 1.47 m

Let's replace the values in the formula

133.30 °C - 131°C = Kb . 1.47m .1

2.30°C / 1.47 m = Kb → 1.56 °C / m

3 0

3 years ago

use the heisenberg uncertainty principle to calculate the uncertainity in meters in the position of 0.68g and traveling at a vel

My name is Ann [436]

Answer:

7.7439×10⁻³¹ m

Explanation:

The expression for Heisenberg uncertainty principle is:

$\Delta x\times \Delta v=\frac {h}{4\times \pi\times m}$

Where m is the mass of the microscopic particle

h is the Planks constant

Δx is the uncertainty in the position

Δv is the uncertainty in the velocity

Given:

mass = 0.68 g = 0.68×10⁻³ kg

Δv = 0.1 m/s

Δx= ?

Applying the above formula as:

$\Delta x\times 0.1=\frac {6.62\times 10^{-34}}{4\times \frac {22}{7}\times 0.68\times 10^{-3}}$

<u>Δx = 7.7439×10⁻³¹ m</u>

8 0

3 years ago