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3 years ago

What is the mole fraction of water in 200g of 95% (by mass) ethanol, C2H5OH? C2H5OH= 46g/mol

1 answer:

5 0

For the given 200 g of 95% ethanol solution, ethanol is 190g and water is 10g. We determine the number of moles per component.
ethanol: (190 g ethanol) / (46 g/mole) = 4.13 moles
water: (10 g water)/(18 g/mole) = 0.55 moles

Total moles of the solution is 4.68 moles

Mole fraction of water: = 0.55 moles/4.68 moles = 0.117

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Calculate the solubility of Mg(OH)2 in water at 25 C. You'll find Ksp data in the ALEKS Data tab. Round your answer to significa

elena-s [515]

Answer:

1.12 × 10⁻⁴ M

Explanation:

Step 1: Write the reaction for the solution of Mg(OH)₂

Mg(OH)₂(s) ⇄ Mg²⁺(aq) + 2 OH⁻(aq)

Step 2: Make an ICE chart

We can relate the solubility product constant (Ksp) with the solubility (S) through an ICE chart.

Mg(OH)₂(s) ⇄ Mg²⁺(aq) + 2 OH⁻(aq)

I 0 0

C +S +2S

E S 2S

The solubility product constant is:

Ksp = 5.61 × 10⁻¹² = [Mg²⁺] × [OH⁻]² = S × (2S)² = 4S³

S = 1.12 × 10⁻⁴ M

8 0

3 years ago

Two 10g blocks, one of copper and one of iron, were heated from 300 K to 400K (a temperature difference of 100 K).

12345 [234]

1) 385 J

2) 450 J

Explanation:

The amount of energy that must be absorbed by a certain substance in order to increase its temperature by $\Delta T$ is given by the equation:

$Q=mC\Delta T$

where

m is the mass of the substance

C is its specific heat capacity

$\Delta T$ is the increase in temperature of the substance

For the block of copper in this problem, we have:

m = 10 g is the mass

$C=0.385 J/gK$ is the specific heat capacity of copper

$\Delta T=400-300 = 100 K$ is the change in temperature

So, the energy absorbed by the block of copper is

$Q=(10)(0.385)(100)=385 J$

Similarly for the block of iron, the energy absorbed by the iron is given by

$Q=mC\Delta T$

where

m is the mass of the block of iron

C is its specific heat capacity of iron

$\Delta T$ is the increase in temperature of the block

Here we have:

m = 10 g is the mass of the block

$C=0.450 J/gK$ is the specific heat capacity of iron

$\Delta T=400-300 = 100 K$ is the change in temperature

So, the energy absorbed by the block of iron is

$Q=(10)(0.450)(100)=450 J$

6 0

3 years ago

Find the density of an 8 gram rock if the water in a graduated cylinder rises from 25.0 mL to

Olin [163]

To measure the density of the stone placed in a graduated cylinder let us follow these steps bellow

Measure the volume of water poured into a graduated cylinder
Place the object in the water and remeasure the volume.
The difference between the two volume measurements is the volume of the object.
Divide the mass by the volume to calculate the density of the object.

<em>We know that the formula for density is given as </em>

Given data

Mass = 8gram

Initial Volume of water in cylinder = 25mL

Final Volume of water in cylinder = 29mL

Hence the volume of the rock = 29-25 = 4mL

Therefore the density of the rock = 8/4 = 2 g/mL

Learn more:

brainly.com/question/17336041

6 0

2 years ago

A solution of the ionic salt NaF

vichka [17]

<h3>A. an acidic............</h3>

8 0

3 years ago

Identify all actions that you should take if you have chipped or broken glassware. Notify your teacher. Have the custodian clean

12345 [234]

Explanation:

If you have chipped or broken glassware then it is very important that you should take precaution yourself by conveying about it to your teacher and class mates.

By doing so you are making everybody aware to be cautious of the chipped or broken glassware.

Also, it is advised that you should dispose of it in the designated glass waste area.

Therefore, we can conclude that all actions that you should take if you have chipped or broken glassware as as follows.

Notify your teacher.

Notify classmates.

Dispose of it in the designated glass waste area.

8 0

3 years ago

Read 2 more answers