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3 years ago

The first three steps in the formation of the sun are listed below.

Chemistry

2 answers:

taurus [48]3 years ago

4 0

C is the answer, I think

erica [24]3 years ago

3 0

Answer:

The contracting nebula flattens into a disk with a bulge at the center.

Explanation:

Sun was formed in solar nebula about 4.5 billion years ago. Solar nebula is a molecular cloud of dust and gases which slowly spun and collapsed due to condensation of gases. The cloud started spinning faster and collapsed. Thereafter, the contracted nebula flattened into a disk and bulge at the center was formed. The temperature and pressure rose till the nuclear fusion reaction started releasing huge amount of energy. The sun was born. The rest of the matter accreted to form planets.

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Consider a voltaic cell where the anode half-reaction is Zn(s) → Zn2+(aq) + 2 e− and the cathode half-reaction is Sn2+(aq) + 2 e

notsponge [240]

Answer: The concentration of $Sn^{2+}$ in the cell is $9.0\times 10^{-3}M$

Explanation:

We are given:

Oxidation half reaction: $Zn(s)\rightarrow Zn^{2+}(aq.)+2e^-$ $E^o_{Zn^{2+}/Zn}=-0.76V$

Reduction half reaction: $Sn^{2+}(aq.)+2e^-\rightarrow Sn(s)$ $E^o_{Sn^{2+}/Sn}=-0.136V$

The substance having highest positive $E^o$ potential will always get reduced and will undergo reduction reaction. Here, fluorine will undergo reduction reaction will get reduced.

Here, tin will undergo reduction reaction and will get reduced.

Oxidation reaction occurs at anode and reduction reaction occurs at cathode.

To calculate the $E^o_{cell}$ of the reaction, we use the equation:

$E^o_{cell}=E^o_{cathode}-E^o_{anode}$

Putting values in above equation, we get:

$E^o_{cell}=-0.136-(-0.76)=0.624V$

To calculate the EMF of the cell, we use the Nernst equation, which is:

$E_{cell}=E^o_{cell}-\frac{0.059}{n}\log \frac{[Mn^{2+}]}{[Cu^{2+}]}$

where,

$E_{cell}$ = electrode potential of the cell = 0.660 V

$E^o_{cell}$ = standard electrode potential of the cell = +0.624 V

n = number of electrons exchanged = 2

$[Zn^{2+}]=2.5\times 10^{-3}M$

$[Sn^{2+}]$ = ?

Putting values in above equation, we get:

$0.660=0.624-\frac{0.059}{2}\times \log(\frac{2.5\times 10^{-3}}{[Sn^{2+}})$

$[Sn^{2+}]=9.0\times 10^{-3}M$

Hence, the concentration of $Sn^{2+}$ ions is $9.0\times 10^{-3}M$

3 0

3 years ago

Consider the reaction given below.

Drupady [299]

Answer:

K = 0.167 s⁻¹

Explanation:

1) Rate law, at a given temperature:

Since all the data are obtained at the same temperature, the equilibrium constant is the same.

Since only reactants A and B participate in the reaction, you assume that the form of the rate law is:

r = K [A]ᵃ [B]ᵇ

2) Use the data from the table

Since the first and second set of data have the same concentration of the reactant A, you can use them to find the exponent b:

r₁ = (1.50)ᵃ (1.50)ᵇ = 2.50 × 10⁻¹ M/s

r₂ = (1.50)ᵃ (2.50)ᵇ = 2.50 × 10⁻¹ M/s

Divide r₂ by r₁: [ 2.50 / 1.50] ᵇ = 1 ⇒ b = 0

Use the first and second set of data to find the exponent a:

r₁ = (1.50)ᵃ (1.50)ᵇ = 2.50 × 10⁻¹ M/s

r₃ = (3.00)ᵃ (1.50)ᵇ = 5.00 × 10⁻¹ M/s

Divide r₃ by r₂: [3.00 / 1.50]ᵃ = [5.00 / 2.50]

2ᵃ = 2 ⇒ a = 1

3) Write the rate law

r = K [A]¹ [B]⁰ = K[A]

This means, that the rate is independent of reactant B and is of first order respect reactant A.

4) Use any set of data to find K

With the first set of data

r = K (1.50 M) = 2.50 × 10⁻¹ M/s ⇒ K = 0.250 M/s / 1.50 M = 0.167 s⁻¹

Result: the rate constant is K = 0.167 s⁻¹

6 0

3 years ago

Use the following image to answer the following questions. A student was performing an experiment using two identical cups made

Anettt [7]

Answer:

The water will eventually become the same temature (A)

3 0

3 years ago

When a strontium atom loses two electrons to form an Sr2+ ion, the electrons are lost from the

kherson [118]

Answer:When a strontium atom loses two electrons, it becomes a(n) cation with a charge of 2+. when any neutral atom loses an electron it becomes cation that is positively charged ions and an ion gets the charge according to the number of electrons loses.

you are very welcome but I may be inaccurate.

6 0

3 years ago

Which of the following is equal to 3.3mm3? A) 3.3 x 10^-6 m^3 B) 3.3 x 10^-9 m^3 C) 3.3 x 10^-6 cm^3 D) 3.3 x 10^-9 cm^3

vazorg [7]

Step 1 - Since 3.3mm^3 = 0.0033cm^3, convert that to 3.3x10^-3 cm^3.

Step 2 - Since 1cm^3 = 1x10^-6 m^3, times 3.3 by that. (3.3 x 1 x 10^-6) = 0.0000033

Step 3 - 0.0000033 = 3.3 x 10 ^-6 m^3, which is your answer choice A.

*if you do not understand, message me and I will go through it more thoroughly!!*

Have a great day!! :)

3 0

3 years ago