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3 years ago

Which process is a chemical change?

Chemistry

1 answer:

dexar [7]3 years ago

6 0

Answer:

Explanation:

1, 2, and 3 are changes in the state of matter. 4 is a chemical reaction because the resulting products are different substances from the first one.

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The decomposition reaction of carbon disulfide to carbon monosulfide and sulfur is first order with k = 2.80 ✕ ✕ 10−7 sec-1 at 1

madam [21]

Answer: a) 1.97 grams of carbon disulfide will remain after 37.0 days.

b) 2.85 grams of carbon monosulfide will be formed after 37.0 days.

Explanation: The decomposition of carbon disulfide is given as:

$CS_2(g)\rightarrow CS(g)+S(g)$

at t=0 4.83g 0 0

at t=37 days 4.83 - x x x

here,

x = amount of $CS_2$ utilised in the reaction

This reaction follows first order kinetics so the rate law equation is:

$k=\frac{2.303}{t}log\frac{A_o}{A}$

where, k = rate constant

t = time

$A_o$ = Initial mass of reactant

A = Final mass of reactant

a) For this, the value of

$k=2.80\times10^{-7}sec^{-1}$

t = 370 days = 3196800 sec

$A_o$ = 4.83

A = 4.83-x

Putting values in the above equation, we get

$2.8\times 10^{-7}sec^{-1}=\frac{2.303}{3196800sec}log\left(\frac{4.83}{4.83-x}\right)$

x = 2.85g

Amount of $CS_2$ remained after 37 days = 4.83 - x

= 1.97g

b) Amount of carbon monosulfide formed will be equal to "x" only which we have calculated in the previous part.

Amount of carbon monosulfide formed = 2.85g

6 0

3 years ago

The atomic number of an atom is equivalent to the number of:

valentinak56 [21]

C the number of protons an neutrons

7 0

3 years ago

the more particles a substance has at a given temperature the more thermal energy it has true or false

Flauer [41]

Answer:

$\huge\boxed{\sf True}$

Explanation:

Temperature and thermal energy are in a direct proportion which means that if temperature of a substance increases, its thermal energy also increases and vice versa.

$\rule[225]{225}{2}$

Hope this helped!

4 0

2 years ago

If the energy of photon emitted from the hydrogen atom is 4.09 x 10-19 J, what is

Aliun [14]

Answer:

486 nm

Explanation:

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

Energy (E) = 4.09×10¯¹⁹ J

Wavelength (λ) =?

Next, we shall determine the frequency of the photon. This can be obtained as follow:

Energy (E) = 4.09×10¯¹⁹ J

Planck's constant (h) = 6.63×10¯³⁴ Js

Frequency (f) =?

E = hf

4.09×10¯¹⁹ = 6.63×10¯³⁴ × f

Divide both side by 6.63×10¯³⁴

f = 4.09×10¯¹⁹ / 6.63×10¯³⁴

f = 6.17×10¹⁴ Hz

Next, we shall determine the wavelength of the photon. This can be obtained as follow:

Frequency (f) = 6.17×10¹⁴ Hz

Velocity of photon (v) = 3×10⁸ m/s

Wavelength (λ) =?

v = λf

3×10⁸ = λ × 6.17×10¹⁴

Divide both side by 6.17×10¹⁴

λ = 3×10⁸ / 6.17×10¹⁴

λ = 4.86×10¯⁷ m

Finally, we shall convert 4.86×10¯⁷ m to nm. This can be obtained as follow:

1 m = 1×10⁹ nm

Therefore,

4.86×10¯⁷ m = 4.86×10¯⁷ m × 1×10⁹ nm / 1 m

4.86×10¯⁷ m = 486 nm

Therefore, the wavelength of the photon is 486 nm

7 0

3 years ago

!!!!!PLEASE HELP!!!!!

ollegr [7]

Answer:

Difference in the potential energy of the reactants and products

Explanation:

The products have a lower potential energy than the reactants, and the sign of ΔH is negative. In an endothermic reaction, energy is absorbed. The products have a higher potential energy than the reactants, and the sign of ΔH is positive.

3 0

2 years ago