Can an elment have more than a single bond with another element ?

the heat of fusion of acetone is 5.7 kJ/mol. Calculate to two significant figures the entropy change when 6.3 mol of acetone mel

shtirl [24]

Answer: The entropy change of the process is $2.0\times 10^2J/K$

Explanation:

To calculate the entropy change for different phase at same temperature, we use the equation:

$\Delta S=n\times \frac{\Delta H_{f}}{T}$

where,

$\Delta S$ = Entropy change

n = moles of acetone = 6.3 moles

$\Delta H_{f}$ = enthalpy of fusion = 5.7 kJ/mol = 5700 J/mol (Conversion factor: 1 kJ = 1000 J)

T = temperature of the system = $-94.7^oC=[273-94.7]=178.3K$

Putting values in above equation, we get:

$\Delta S=\frac{6.3mol\times 5700J/mol}{178.3K}\\\\\Delta S=201.4J/K=2.0\times 10^2J/K$

Hence, the entropy change of the process is $2.0\times 10^2J/K$

4 0

3 years ago

What is the total number of moles represented by 20 grams of CACO3

Nutka1998 [239]

Answer:

B. 0.2.

Explanation:

We can use the relation:

n = mass/molar mass

mass of CaCO₃ = 20 g, molar mass of CaCO₃ = 100.0869 g/mol.

∴ n = mass/molar mass = (20 g)/(100.0869 g/mol) = 0.1998 ≅ 0.2 mol.

So, the right choice is: B. 0.2.

8 0

3 years ago

Using Argn (n= –2, –1, 0, +1, +2, etc.) to represent the different charge species of Arginine, what is the dominant species of A

fredd [130]

Answer:

Explanation:

From the sorensen equation; pH = -Log[H+]

2.7 = -Log[H+]

H+ = 10^-2.7

H+ = 0.001995M = Hydrogen ion concentration

Basically, the more the charges, the higher the hydrogen ion concentration stand vice versa. +2 has the highest concentration.

6 0

2 years ago

.What threatens the newly hatched chicks?

marysya [2.9K]

Answer:

rats. that's all i know of Just about everything except the mother hen if they are natural hatch. Even when you incubate them there are threats. The healthy chicks will mob the weak ones, the older chicks (even by a day) will pick on the younger ones. Temperature extremes will threaten them as they need warm, humid conditions with gradual drops in surrounding temps in the brooder box. Early disease is sometimes a problem and all chicks should be started on medicated chick feed for the first few weeks to prevent several digestive diseases. Even the water dispenser can be a threat as newly hatched chicks will immerse themselves in an open water container so care should be taken to supply water in a self feeding covered dish.

Explanation:

3 0

2 years ago

Read 2 more answers

A gas mixture of Ne and Ar has a total pressure of 4.00 atm and contains 16.0 mol of gas. If the partial pressure of Ne is 2.75

Stolb23 [73]

Answer:

5 moles of Argon is present in the mixture.

Explanation:

Total pressure of the gaseous mixture = 4 atm

Total number of moles = 16

Partial pressure of Ne = 2.75 atm

By Dalton's law of partial pressure, the total pressure of gaseous mixture is the sum of partial pressures of individual gases which are non-reactive.

Hence:

$P_{total}=P_{Ar}+P_{Ne}\\4=P_{Ar}+2.75\\P_{Ar}=1.25\ atm$

Also :

Partial pressure = mole fraction*total pressure

$P_{Ar}=X_{Ar}P_{total}$

$X_{Ar}=\frac{1.25}{4}=0.3125$

$\frac{n_{Ar}}{n_{total}}=0.3125\\n_{Ar}=5$

∴Number of moles of Argon = 5

4 0

3 years ago