1.05kg of aluminum what is the heat capacity ?

A solution contains naphthalene (C10H8) dissolved in hexane (C6H14) at a concentration of 13.06% naphthalene by mass. Calculate

worty [1.4K]

Answer: The vapor pressure of the solution at $25^0C$ is 137 torr

Explanation:

As the relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.

The formula for relative lowering of vapor pressure will be,

$\frac{p^o-p_s}{p^o}=i\times x_2$

where,

$\frac{p^o-p_s}{p^o}$ = relative lowering in vapor pressure

i = Van'T Hoff factor = 1 (for non electrolytes)

$x_2$ = mole fraction of solute = $\frac{\text {moles of solute}}{\text {total moles}}$

Given : 13.06 g of napthalene is present in 100 g of solution, thus (100-13.06) g = 86.94 g of hexane

moles of solute (napthalene) = $\frac{\text{Given mass}}{\text {Molar mass}}=\frac{13.06g}{128g/mol}=0.102moles$

moles of solvent (hexane) = $\frac{\text{Given mass}}{\text {Molar mass}}=\frac{86.94g}{86g/mol}=1.01moles$

Total moles = moles of solute (napthalene) + moles of solvent (hexane) = 0.102 + 1.01 = 1.112

$x_2$ = mole fraction of solute (napthalene) = $\frac{0.102}{1.112}=0.0917$

$\frac{151-p_s}{151}=1\times 0.0917$

$p_s=137torr$

Thus the vapor pressure of the solution at $25^0C$ is 137 torr

7 0

2 years ago

A graduated cylinder is filled with 50.7 mL of water. If a 10.0 g piece of zinc metal is added to the water, and the volume rise

Triss [41]

Answer:

<h3>The answer is 7.14 g/mL</h3>

Explanation:

The density of a substance can be found by using the formula

$density = \frac{mass}{volume} \\$

From the question

mass = 10 g

volume = final volume of water - initial volume of water

volume = 52.1 - 50.7 = 1.4 mL

We have

$density = \frac{10}{1.4} \\ = 7.142857...$

We have the final answer as

Hope this helps you

5 0

3 years ago

20. A compound's empirical formula is C5H5O If the molecular mass of the compound is

MA_775_DIABLO [31]

Answer:

Just use a text book.. So that you get the concept

8 0

3 years ago

Sulfuric acid is formed when sulfur dioxide reacts with oxygen and water. Write a balanced chemical equation for the reaction. (

Nesterboy [21]

Balanced chemical equation for the reaction is:

2S $O_{2}$ (g) + $O_{2}$ (g)+ 2 $H_{2}$ O (l) ⇒ $H_{2} S_{} O_{4}$

Moles of $H_{2} S_{} O_{4}$ formed is 5.75 moles.

Moles of oxygen used is 5.75 moles in the reaction.

Explanation:

Data given:

moles of S $O_{2}$ = 11.5 moles

moles of $H_{2} S_{} O_{4}$ = ?

Moles of $O_{2}$ needed =?

balanced equation with states of matter =?

Balanced chemical reaction under STP condition is given as:

2S $O_{2}$ (g) + $O_{2}$ (g) + 2 $H_{2}$ O (l) ⇒ $H_{2} S_{} O_{4}$

From the balanced reaction 2 moles of sulphur dioxide reacted to form 1 mole of sulphuric acid:

so, from 11.5 moles of S $O_{2}$ , x moles of $H_{2} S_{} O_{4}$ is formed

$\frac{1}{2} =\frac{x}{11.5}$

2x = 11.5

x = 5.75 moles of sulphuric acid formed.

From the balanced reaction 1 mole of oxygen reacted to form 1 mole of sulphuric acid.

when 11.5 moles of Sulphur dioxide reacted then oxygen in the reaction is 5.75 moles.

7 0

3 years ago

In a compound, chemical energy is _______________ when bonds break.

Romashka-Z-Leto [24]

Answer:

In a compound, chemical energy is _____required__________ when bonds break.

6 0

2 years ago