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Cloud [144]
3 years ago
7

6.What are the mass numbers of; hydrogen, heliumand boron? I승​

Chemistry
1 answer:
madreJ [45]3 years ago
3 0
The mass number of hydrogen is 2

The mass number of helium is 4

The mass number of boron is 7

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Fill in the blank.<br> 9.31x103 = [ ? ]x 105
Igoryamba

Answer:

The answer is 0.0931 × 10^5

Hope this helps.

6 0
4 years ago
The rate constant of a reaction is 5.8 × 10−3 s−1 at 25°c, and the activation energy is 33.6 kj/mol. what is k at 75°c? enter yo
sergij07 [2.7K]

Answer:

k₂ = 4.06 x 10⁻² s⁻¹.

Explanation:

  • From Arrhenius law: <em>K = Ae(-Ea/RT)</em>

where, K is the rate constant of the reaction.

A is the Arrhenius factor.

Ea is the activation energy.

R is the general gas constant.

T is the temperature.

  • At different temperatures:

<em>ln(k₂/k₁) = Ea/R [(T₂-T₁)/(T₁T₂)]</em>

k₁ = 5.8 × 10⁻³ s⁻¹, k₂ = ??? , Ea = 33600 J/mol, R = 8.314 J/mol.K, T₁ = 298.0 K, T₂ = 348.0 K.

  • ln(k₂/5.8 × 10⁻³ s⁻¹) = (33600 J/mol / 8.314 J/mol.K) [(348.0 K - 298.0 K) / (298.0 K x 348.0 K)] = (4041.37) (4.82 x 10⁻⁴) = 1.9479.
  • Taking exponential of both sides:

(k₂/5.8 × 10⁻³ s⁻¹) = 7.014.

∴ k₂ = 4.06 x 10⁻² s⁻¹.

3 0
3 years ago
What is the answer? Please
Mrac [35]

Answer:

true

Explanation:

what is the answer? please

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