The diagram below represents a plan cell Letter X represents a structure in the cell

a solution of unknown molecular substance is prepared by dissolving 0.50g of the unknown in 8.0g of benzene. the solution freeze

spayn [35]

Answer:

THE MOLAR MASS OF THE UNKNOWN MOLECULAR SUBSTANCE IS 200 G/MOL.

Explanation:

Mass of the unknown substance = 0.50 g

Freezing point of the solution = 3.9 °C

Freezing point of pure benzene = 5.5 °C

Freezing point dissociation constant Kf = 5.12°C/m

First, calculate the temperature difference between the freezing point of pure benzene and the final solution freezing point.

Change in temperature = 5.5 -3.9 = 1.6 °C

Next is to calculate the number of moles or molarity of the compound that dissolved.

Using the formula:

Δt = i Kf m

Assume i = 1

So,

1.6 °C = 1 * 5.12 * x/ 0.005 kg of benzene

x = 1.6 * 0.008 / 5.12

x = 0.0128 / 5.12

x = 0.0025 moles.

Next is to calculate the molar mass using the formula, molarity = mass / molar mass

Molar mass = mass / molarity

Molar mass = 0.50 g /0.0025

Molar mass = 200 g/mol

Hence, the molar mass of the unknown compound is 200 g/mol

6 0

2 years ago

How many grams of Sg is required to produce 83.10 g SF6? S: +24F-->8SF

ozzi

Answer : The mass of $S_8$ required is 18.238 grams.

Explanation : Given,

Mass of $SF_6$ = 83.10 g

Molar mass of $SF_6$ = 146 g/mole

Molar mass of $S_8$ = 256.52 g/mole

The balanced chemical reaction is,

$S_8+24F_2\rightarrow 8SF_6$

First we have to determine the moles of $SF_6$ .

$\text{Moles of }SF_6=\frac{\text{Mass of }SF_6}{\text{Molar mass of }SF_6}=\frac{83.10g}{146g/mole}=0.569moles$

Now we have to determine the moles of $S_8$ .

From the balanced chemical reaction we conclude that,

As, 8 moles of $SF_6$ produced from 1 mole of $S_8$

So, 0.569 moles of $SF_6$ produced from $\frac{0.569}{8}=0.0711$ mole of $S_8$

Now we have to determine the mass of $S_8$ .

$\text{Mass of }S_8=\text{Moles of }S_8\times \text{Molar mass of }S_8$

$\text{Mass of }S_8=(0.0711mole)\times (256.52g/mole)=18.238g$

Therefore, the mass of $S_8$ required is 18.238 grams.

7 0

3 years ago

What is a caliper used for

photoshop1234 [79]

To measure the distance between two opposite sides of an object

8 0

3 years ago

Please explain how to do it as well!

kogti [31]

Answer:

a. $\bold{C_{6}H_{12}O_{6}\rightarrow 6CO_{2}+6H_{2}O}$

△H=−72 kcal

The energy required for production of 1.6 g of glucose is [molecular mass of glucose is 180 gm]

b.

$\bold{Fe_{2}(SO_{4})_{3}+3Ba(OH)_{2}\rightarrow 3BaSO_{4}+2Fe(OH)_{3}}$

The iron(III) ions and chloride ions remain aqueous and are spectator ions in a reaction that produces solid barium sulfate.

7 0

3 years ago

Read 2 more answers

When the potential difference across a lamp is 3.3V the current is 0.15 calculate the resistance of the lamp and give the unit

marissa [1.9K]

Answer:

22Ω

Explanation:

Given parameters:

Potential difference = 3.3V

Current = 0.15A

Unknown:

Resistance = ?

Solution:

According to ohm's law, potential difference, current and resistance are related by the expression below;

V = I R

where V is the voltage

I is the current

R is the resistance

3.3 = 0.15 x R

R = $\frac{3.3}{0.15}$ = 22Ω

6 0

2 years ago

The diagram below represents a plan cell Letter X represents a structure in the cell ​

The diagram below represents a plan cell Letter X represents a structure in the cell