A qué se le conoce como el reactivo limitante

What is the boiling point of a solution made by adding 6.69 g of magnesium chloride to 250.0 g of water?. Use the formula of the

olya-2409 [2.1K]

Answer:

100.432ºC

Explanation:

Ebullioscopy is the elevation of the boiling point of a solvent that has a solute nonvolatile dissolved. The change in the temperature may be calculated by Raoult's law:

ΔT = Kb.W.i

Where ΔT is the temperature change, Kb is the ebullioscopy constant, W is the molality and i is the Van't Hoff factor, which determinates the particles that affect the proper.

The molality is:

W = m1/(M1xm2)

Where m1 is the solute mass (in g), M1 is the molar mass of the solute, and m2 is the mass of the solvent (in kg).

The Van't Hoff factor is the number of final particles divided by the number of initial particles. Magnesium is from froup 2, so it forms the cation Mg⁺², and chlorine ins from group 7 and forms the anion Cl⁻, the salt is MgCl₂ and dissociates:

MgCl₂ → Mg⁺²(aq) + 2Cl⁻(aq)

So, it has 1 particle in initial, and 3 in final (1 Mg⁺² and 2 Cl⁻). So:

i = 3/1 = 3.

The molar mass of MgCl₂ is: 24.3 + 2x35.5 = 95.3 g/mol, m1 = 6.69g, m2 = 0.250 kg, so:

W = 6.69/(95.3x0.250)

W = 0.281 m

Then:

ΔT = 0.512x0.281x3

ΔT = 0.432ºC

The normal boling point of water is 100ºC, so

T - 100 = 0.432

T = 100.432ºC

6 0

3 years ago

Which of the following species is a molecular element?1. neon 2. carbon dioxide3. chlorine 4. sodium 5. none of the above

babymother [125]

Answer:

2

Explanation:

4 0

4 years ago

A sample of an unkown liquid has a volume of 30.0 ml and a mass of 6 g.What is its density?

sineoko [7]

0.2 g/mL

We can use the density formula D = M/V.

D = 6 g/30.0 mL = 0.2 g/mL

6 0

4 years ago

The law of conservation of mass states that mass is neither created nor destroyed during a chemical reaction. This can be gleane

GenaCL600 [577]

Answer : The total mass of oxygen gas released in the reaction will be, 12.8 grams

Explanation :

Law of conservation of mass : It states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.

This also means that total mass on the reactant side must be equal to the total mass on the product side.

The balanced chemical reaction will be,

$2MgO\rightarrow 2Mg+O_2$

According to the law of conservation of mass,

Total mass of reactant side = Total mass of product side

Total mass of $2MgO$ = Total mass of $2Mg+O_2$

or,

Total mass of $2MgO$ = Mass of $2Mg$ + Mass of $O_2$

As we are given :

Total mass of $MgO$ = 16.12 grams

The mass of $Mg$ = 9.72 grams

So,

Total mass of $2MgO$ = Mass of $2Mg$ + Mass of $O_2$

$2\times 16.12g=2\times 9.72g+\text{Mass of }O_2$

$\text{Mass of }O_2=32.24g-19.44g=12.8g$

Therefore, the total mass of oxygen gas released in the reaction will be, 12.8 grams

8 0

3 years ago

When 25.0 ml of 0.500 m h2so4 is added to 25.0 ml of 1.00 m koh in a coffee-cup calorimeter at 23.50°c, the temperature rises to

AlladinOne [14]

The chemical reaction that occurs between the given substances is a neutralization reaction as shown below :

H_2SO_4 + 2KOH -> K_2SO_4 + 2H_2O

1 mol 2 mol 1 mol 2 mol

The number of moles of the given substances is calculated as shown :

Number of moles of H_2SO_4 = 25.0 mL x 0.50 M = 12.5 millimoles

Number of moles of KOH = 25.0 mL x 1.00 M = 25.0 millimoles

As 1 mol of sulfuric acid reacts with 2 mol of KOH to give 2 mol of water, 12.5 millimoles of sulfuric acid completely reacts with 25.0 millimoles of KOH to give 25.0 millimoles of water.

Total volume of the solution = 25.0 mL + 25.0 mL = 50.0 mL.

Density of water is 1 g/mL. Use this to calculate the mass of the solution.

Mass of the solution – 50.0 mL x 1 g/mL = 50.0

The specific heat of water is 4.184 J/gK. The temperature of the solution is increased from 23.5 degrees Celsius to 30.17 degrees Celsius.

The amount of heat released = 4.184 J/gK x 50.0 g x (30.17C – 23.50C) 1395 J

The amount of heat released per one mole of water formed can be calculated as shown :

The amount of heat released for formation of mole water = 1395 J / (25.0 m mol x 1mol/1000 m mol)

= 55,800 J

8 0

3 years ago