Is this the correct formula for magnesium acetate? Mg(C2H3O)2

What is the entropy change for freezing 2.71 g of C2H5OH at 158.7 K? ∆H = −4600 J/mol. Answer in units of J/K.

Ira Lisetskai [31]

Answer:

-1.71 J/K

Explanation:

To solve this problem we use the formula

ΔS = n*ΔH/T

Where n is mol, ΔH is enthalpy and T is temperature.

ΔH and T are already given by the problem, so now we calculate n:

Molar Mass C₂H₅OH = 46 g/mol

2.71 g C₂H₅OH ÷ 46g/mol = 0.0589 mol

Now we calculate ΔS:

ΔS = 0.0589 mol * −4600 J/mol / 158.7 K

ΔS = -1.71 J/K

4 0

3 years ago

A chemical reaction takes place inside a flask submerged in a water bath. The water bath contains 8.10kg of water at 33.9 degree

victus00 [196]

Explanation:

The given data is as follows.

q = 69.0 kJ = 69000 J (as 1 kJ = 1000 J),

mass (m) = 8.10 kg = 8100 g (as 1 kg = 1000 g)

$T_{i} = 33.9^{o}C$ = (33.9 + 273) K = 306.9 K

C = 4.18 J/gK

As we know that the relation between heat and change in temperature is as follows.

q = $m \times C \times \Delta T$

Putting the values into the above formula to calculate the final temperature as follows.

q = $m \times C \times \Delta T$

69000 J = $8100 g \times 4.18 J/g K \times (T_{f} - 306.9 K)$

69000 J = $33858 \times (T_{f} - 306.9 K)$

$(T_{f} - 306.9 K)$ = 2.037 K

$T_{f}$ = (2.037 + 306.9) K

= 308.9 K

or, = 309 K (approx)

Thus, we can conclude that the new temperature of the water bath is 309 K.

5 0

3 years ago

What’s an example of two subsystems working together in the human body systems

7nadin3 [17]

Answer:

your brain and you hand

Explanation:

because your hand tells you what to do with that hand

6 0

4 years ago

3. Students were measuring distances and found one to be 2.04 m. When they asked the teacher if their measurement was correct, t

Vlada [557]

Answer:

5.56

Explanation:

4 0

3 years ago

If 50.0 g of KCl reacts with 50.0 g of O2 to produce KClO3 according to the following equation, how many grams of KClO3 will be

Sliva [168]

Answer:

A. 82.2g of KClO3

B. Word equation:

50g of KCl react with 50g of O2 to produce 82.2g of KClO3

C. Formula equation:

2KCl + 3O2 —> 2KClO3

Explanation:

The balanced equation for the reaction. This is given below:

2KCl + 3O2 —> 2KClO3

Next, we shall determine the masses of KCl and O2 that reacted and the mass of KClO3 produced from the balanced equation. This is illustrated below:

Molar Mass of KCl = 39 + 35.5 = 74.5g/mol

Mass of KCl from the balanced equation = 2 x 74.5 = 149g

Molar Mass of O2 = 16x2 = 32g/mol

Mass of O2 from the balanced equation = 3 x 32 = 96g

Molar Mass of KClO3 = 39 + 35.5 + (16x3) = 122.5g/mol

Mass of KClO3 from the balanced equation = 2 x 122.5 = 245g

Summary:

From the balanced equation above:

149g of KCl reacted.

96g of O2 reacted.

245g of KCl were produced.

Next, we shall determine the limiting reactant. This is illustrated below:

From the balanced equation above,

149g of KCl reacted with 96g of O2.

Therefore, 50g of KCl will react with = (50 x 96)/149 = 32.21g of O2.

Since a lesser mass of O2 ( i.e 32.21g) than what was given (i.e 50g) is needed to react completely with 50g of KCl, therefore, KCl is the limiting reactant and O2 is the excess reactant.

A. Determination of the mass of KClO3 produced from the reaction.

In this case the limiting reactant will be used.

From the balanced equation above,

149g of KCl reacted To produce 245g of KClO3.

Therefore, 50g of KCl will react to produce = (50 x 245)/149 = 82.2g of KClO3.

Therefore, 82.2g of KClO3 is produced from the reaction.

B. Word equation:

50g of KCl react with 50g of O2 to produce 82.2g of KClO3.

C. Formula equation:

2KCl + 3O2 —> 2KClO3

4 0

4 years ago