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3 years ago

What amount of heat is released when the temperature of 450.0 g of a

Chemistry

1 answer:

Molodets [167]3 years ago

5 0

Answer:

$\boxed {\boxed {\sf 4038.48 \ Joules}}$

Explanation:

Since we are given the mass, specific heat, and change in temperature, we should use this formula for heat:

$q=mc\Delta T$

The substance's mass is 450.0 grams, the specific heat is 1.264 J/g°C, and the change in temperature is 7.1 °C.

$m= 450.0 \ g \\c= 1.264 \ J/g \textdegree C\\\Delta T= 7.1 \ \textdegree C$

Substitute the values into the formula.

$q= (450.0 \ g)(1.264 \ J/g \textdegree C)(7.1 \ \textdegree C)$

Multiply the first 2 values together. The grams will cancel out.

$q= 568.8 \ J/ \textdegree C (7.1 \ \textdegree C)$

Multiply again. This time, the degrees Celsius cancel out.

$q= 4038.48 \ J$

<u>4038.48 Joules</u> of heat energy are released.

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Describe the composition of humus and why it is an effective organic fertilizer.

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Answer:

Humus, which ranges in colour from brown to black, consists of about 60 percent carbon, 6 percent nitrogen, and smaller amounts of phosphorus and sulfur. As humus decomposes, its components are changed into forms usable by plants.

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2 years ago

What is this equation balanced?

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This equation is impossible. NaSO4 is non-existent. Did you mean Na2SO4?

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3 years ago

A company wants to develop audio speakers using an inexpensive type of plastic that has a very high quality of sound output. Whi

olga nikolaevna [1]

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3 years ago

A reactant decomposes with a half-life of 29.5 s when its initial concentration is 0.229 M. When the initial concentration is 0.

Dmitrij [34]

Answer :

The order of reaction is, 0 (zero order reaction).

The value of rate constant is, $0.00388Ms^{-1}$

Explanation :

Half life : It is defined as the time in which the concentration of a reactant is reduced to half of its original value.

The general expression of half-life for nth order is:

$t_{1/2}\propto \frac{1}{[A_o]^{n-1}}$

or,

$\frac{t_{1/2}_1}{t_{1/2}_2}=\frac{[A_2]^{n-1}}{[A_1]^{n-1}}$

or,

$n=\left(\frac{\log\frac{(t_{1/2})_1}{(t_{1/2})_2}}{\log\frac{(A)_2}{(A)_1}}\right )+1$ .............(1)

where,

$t_{1/2}$ = half-life of the reaction

n = order of reaction

[A] = concentration

As we are given:

Initial concentration of A = 0.229 M

Final concentration of A = 0.639 M

Initial half-life of the reaction = 29.5 s

Final half-life of the reaction = 82.3 s

Now put all the given values in the above formula 1, we get:

$n=\left (\frac{\log \frac{29.5}{82.3}}{\log\frac{0.639}{0.229}}\right )+1$

$n=0.000196\approx 0$

Thus, the order of reaction is, 0 (zero order reaction).

Now we have to determine the rate constant.

To calculate the rate constant for zero order the expression will be:

$t_{1/2}=\frac{[A_o]}{2k}$

When,

$t_{1/2}$ = 29.5 s

$[A_o]$ = 0.229 M

$29.5s=\frac{0.229M}{2k}$

$k=0.00388Ms^{-1}$

Thus, the value of rate constant is, $0.00388Ms^{-1}$

4 0

3 years ago

18. For the recoton 2H2 + O2 + 2H20. how many moles of water can be produced from 23.2 mol of

grigory [225]

Answer:

23.2 mols

Explanation:

(23.2 mol H2)(2 mol H2O) /(2 mol H2) = 23.2 mol H2O

you have to do stoichiometry - so start of with what you are given, which is 23.2 mols of hydrogen, then to cancel out mols of hydrogen, divide by what is in the equation: so 23.2 mols H2 / 2 mols H2. Next, to get mols of H2O multiply that number by the mols of water in the equation.

this answer makes sense because as you can see in the equation, there are 2 H2:2 H2O, so the amounts should be the same.

hope this helps! make sure to practice because it is ESSENTIAL that you understand this, especially if you plan on taking ap chem. good luck! :)

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3 years ago