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3 years ago

Which aqueous solution has the highest boiling point?a. 0.20 M NaClb. 0.10 M CaCl2c. 0.1 M Ga2(SO4)3d. 0.2 M C6H12O6

Chemistry

1 answer:

abruzzese [7]3 years ago

3 0

Answer:

c. 0.1 M Ga₂(SO₄)₃

Explanation:

The boiling point increasing of a solvent due the addition of a solute follows the formula:

ΔT = K*m*i

<em>Where K is boiling point increasing constant (Depends of the solute), m is molality = molarity when solvent is water, and i is Van't Hoff factor.</em>

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That means the option with the higher m*i will be the solution with the highest boiling point:

a. NaCl has i = 2 (NaCl dissociates in Na⁺ and Cl⁻ ions).

m* i = 0.20*2 = 0.4

b. CaCl₂; i = 3. 3 ions.

m*i= 0.10M * 3 = 0.3

c. Ga₂(SO₄)₃ dissolves in 5 ions. i = 5

m*i = 0.10M*55 = 0.5

d. C₆H₁₂O₆ has i = 1:

m*i = 0.2M*1 = 0.2

The solution with highest boiling point is:

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`Carbon Dioxide and Water are the _______ in a chemical reaction. 2. Reactants are also called the starting _______ in a chemica

natima [27]

The answer would be elector literally

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2 years ago

If 15.6 grams of copper (ii) chloride react with 20.2 grams of sodium nitrate how many grams of sodium chloride can be formed? W

olasank [31]

Answer:

- 13.56 g of sodium chloride are theoretically yielded.

- Limiting reactant is copper (II) chloride and excess reactant is sodium nitrate.

- 0.50 g of sodium nitrate remain when the reaction stops.

- 92.9 % is the percent yield.

Explanation:

Hello!

In this case, according to the question, it is possible to set up the following chemical reaction:

$CuCl_2+2NaNO_3\rightarrow 2NaCl+Cu(NO_3)_2$

Thus, we can first identify the limiting reactant by computing the yielded mass of sodium chloride, NaCl, by each reactant via stoichiometry:

$m_{NaCl}^{by\ CuCl_2}=15.6gCuCl_2*\frac{1molCuCl_2}{134.45gCuCl_2} *\frac{2molNaCl}{1molCuCl_2} *\frac{58.44gNaCl}{1molNaCl} =13.56gNaCl\\\\m_{NaCl}^{by\ NaNO_3}=20.2gNaNO_3*\frac{1molNaNO_3}{84.99gNaNO_3} *\frac{2molNaCl}{2molNaNO_3} *\frac{58.44gNaCl}{1molNaCl} =13.89gNaCl$

Thus, we infer that copper (II) chloride is the limiting reactant as it yields the fewest grams of sodium chloride product. Moreover the formed grams of this product are 13.56 g. Then, we take 13.56 g of sodium chloride to compute the consumed mass sodium nitrate as it is in excess:

$m_{NaNO_3}^{by\ NaCl}=13.56gNaCl*\frac{1molNaCl}{58.44gNaCl}*\frac{2molNaNO_3}{2molNaCl} *\frac{84.99gNaNO_3}{1molNaNO_3}=19.72gNaNO_3$

Therefore, the leftover of sodium nitrate is:

$m_{NaNO_3}^{leftover}=20.2g-19.7g=0.5gNaNO_3$

Finally, the percent yield is computed via:

$Y=\frac{12.6g}{13.56g} *100\%\\\\Y=92.9\%$

Best regards!

6 0

2 years ago

c. The reaction Br2 (l) --> Br2 (g) has ΔH = 30.91 kJ/mol and ΔS = 93.3 J/mol·K. Use this information to show (within close a

egoroff_w [7]

Answer:

The answer to your question is given below.

Explanation:

From the question given above, the following data were obtained:

Br₂ (l) —> Br₂(g)

Enthalpy change (ΔH) = 30.91 KJ/mol

Entropy change (ΔS) = 93.3 J/mol·K

Boiling temperature (T) =?

Next, we shall convert 30.91 KJ/mol to J/mol. This can be obtained as follow:

1 KJ/mol = 1000 J/mol

Therefore,

30.91 KJ/mol = 30.91 × 1000

30.91 KJ/mol = 30910 J/mol

Thus, 30.91 KJ/mol is equivalent to 30910 J/mol.

Finally, we shall determine the boiling temperature of bromine. This can be obtained as follow:

Enthalpy change (ΔH) = 30910 J/mol

Entropy change (ΔS) = 93.3 J/mol·K

Boiling temperature (T) =?

ΔS = ΔH / T

93.3 = 30910 / T

Cross multiply

93.3 × T = 30910

Divide both side by 93.3

T = 30910 / 93.3

T = 331.29 K

Thus, the boiling temperature of bromine is 331.29 K

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3 years ago

Purification of chromium can be achieved by electrorefining chromium from an impure chromium anode onto a pure chromium cathode

mylen [45]

Answer:

696 h

Explanation:

Let's consider the reduction of Cr³⁺.

Cr³⁺(aq) + 3e⁻ → Cr(s)

We can establish the following relations.

The molar mass of Cr is 52.0 g/mol.
1 mol of Cr is deposited when 3 moles of e⁻ circulate.
1 mole of e⁻ has a charge of 96468 c (Faraday's constant).
1 A = 1 c/s
1 h = 3600 s

<em>How many hours will it take to plate 13.5 kg of chromium onto the cathode if the current passed through the cell is held constant at 30.0 A?</em>

$13.5 \times 10^{3} gCr.\frac{1molCr}{52.0gCr} .\frac{3mol/e^{-} }{1molCr} .\frac{96468c}{1mol/e^{-}} .\frac{1s}{30.0c} .\frac{1h}{3600s} =696 h$

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3 years ago

Explain,using your own example ,why you must always give a unit when reporting a measurement

Sphinxa [80]

Answer : Unit of any measurement can be defined as a definite magnitude of a given quantity, which is defined and adopted by convention or by law, that is widely used as a standard for measurement of the same kind of quantity. If the unit system was not given to the measurements we would haphazardly complicate the calculations.

Example : If someone wrote 500 in the paper as a answer to a question. But forgot to mention the units of the measurements. It can be misinterpreted by anyone as there are no units written besides the number (unit less). Complications grow. One cannot simply predict is it 500 m? 500 g? 500 mL? 500 km? 500 s? or 500 M? anything can be guessed. To be specific about the answer to any problem we should always use units. Which will help to narrow down the approach of any problem and give a measurable related quantity about the associated problem.

4 0

3 years ago