All categories

3 years ago

The enthalpy of formation of CO2 at 25oC is -393.51 kJ/mol. What is the enthalpy of formation at 500 oC?

Chemistry

1 answer:

Kisachek [45]3 years ago

6 0

Answer:

-375.9_KJ/(mol)

Explanation:

H(T2 ) ≈ H(T1)+CPΔT

Specific heat of Carbon is 0.71 J/g K.

At 283.15 the heat capacity is 37.12 J/(mol*K)

Kirchhoff's law

H(T2 ) ≈ H(T1)+CPΔT

Where

H(T1) and H(T2 ) are the heat of formation of CO2 at temperatures T1 and T2

CP is the heat capacity

Thus we have and ΔT is the temperature change

H(T2 ) ≈ -393.51×10^3+CP×(500-25)

= -393.51×10^3+37.12×(500-25)

= -375878 J/(mol)

= -375.9KJ/(mol)

You might be interested in

Calculate the percent yield of benzyl alcohol Sue obtained when doing the following reaction. Sue started with 2.1 g of benzoic

Pachacha [2.7K]

Answer:

The percent yield is 116.6 %

Explanation:

Step 1: Data given

Mass of benzoic anhydride = 2.1 grams

Mass of sodium borohydride = 0.15 grams

Molar mass of benzoic anhydride = 226.23 g/mol

Molar mass of NaBH4 = 37.83 g/mol

Mass of benzyl alcohol produced = 0.5 grams

Step 2: The balanced equation

C14H10O3 + NaBH4 → C7H6O2 + C7H8O + NaB

Step 3: Calculate moles of C14H10O3

Moles C14H10O3 = Mass / molar mass

Moles C14H10O3 = 2.10 grams / 226.23 g/mol

Moles C14H10O3 = 0.00928 moles

Step 4: Calculate moles NaBH4

Moles NaBH4 = 0.150 grams / 37.83 g/mol

Moles NaBH4 = 0.00397 moles

Step 5: Calculate limiting reactant

For 1 mol of C14H10O3 we need 1 mol of NaBH4 to produce 1 mol of C7H8O

NaBH4 is the limiting reactant. It will completely be consumed ( 0.00397 moles).

C14H10O3 is in excess. There will react 0.00397 moles.

There will remain 0.00928 - 0.00397 = 0.00531 moles

Step 6: Calculate moles of C7H8O

For 1 mol of C14H10O3 we need 1 mol of NaBH4 to produce 1 mol of C7H8O

For 0.00397 of C14H10O3 we need 0.00397 mol of NaBH4 to produce 0.00397 mol of C7H8O

Step 7: Calculate mass of C7H8O

Mass of C7H8O = Moles * molar mass

Mass of C7H8O = 0.00397 moles * 108.14 g/mol

Mass of C7H8O = 0.429 grams = theoretical yield

Step 8: Calculate % yield

% yield = (actual yield/ theoretical yield) * 100%

% yield = 0.5/0.429) *100 %

% yield = 116.6 %

The percent yield is 116.6 %

3 0

4 years ago

If a compound has a composition of 82% nitrogen and 18% hydrogen, what is the empirical formula for this compound

Damm [24]

Answer: The empirical formula for the given compound is $NH_3$

Explanation : Given,

Percentage of H = 18 %

Percentage of N = 82 %

Let the mass of compound be 100 g. So, percentages given are taken as mass.

Mass of H = 18 g

Mass of N = 82 g

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Hydrogen = $\frac{\text{Given mass of Hydrogen}}{\text{Molar mass of Hydrogen}}=\frac{18g}{1g/mole}=18moles$

Moles of Nitrogen = $\frac{\text{Given mass of nitrogen}}{\text{Molar mass of nitrogen}}=\frac{82g}{14g/mole}=5.8moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 5.8 moles.

For Hydrogen = $\frac{18}{5.8}=3.10\approx 3$

For Nitrogen = $\frac{5.8}{5.8}=1$

Step 3: Taking the mole ratio as their subscripts.

The ratio of H : N = 3 : 1

Hence, the empirical formula for the given compound is $NH_3$

3 0

3 years ago

Boxes on trees in swamps give wood ducks a place to build their nests platforms built on top of telephone poles provide a place

Rus_ich [418]

These artificial homes preserve the resources in the animal's environment and increases population size.

<h3>What is Population size?</h3>

This is defined as the number of organisms in a population at a given place and time.

Since the resources used are artificial, they are preserved with an increase in the population due to reproduction.

Read more about Population size here brainly.com/question/1502078

#SPJ1

8 0

2 years ago

Who can help me on this one ?

Bogdan [553]

Answer:

eight strong bonds to the atoms that it touches and six weaker bonds to the atoms it almost touches. This makes it easier to understand why a metal might prefer the body-centered cubic structure to the hexagonal or cubic closest-packed structure.

6 0

3 years ago

How do you figure out how many isotopes an element has?

Helen [10]

by counting the isoto

7 0

3 years ago