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Sever21 [200]
3 years ago
12

Boron has primarily two isotopes, one with an atomic mass of 11.0 amu and another with an atomic mass of 10.0 amu. If the abunda

nce of the boron atom with a mass of 11.0 amu is 18.9 percent and the abundance of the other isotope is 81.1 percent, what would be the atomic mass of the boron atom
Chemistry
1 answer:
Masja [62]3 years ago
5 0

Answer:

The atomic mass of the boron atom would be <em>10.135</em>

Explanation:

This is generally known as relative atomic mass.

Relative atomic mass or atomic weight is a physical quantity defined as the ratio of the average mass of atoms of a chemical element in a given sample to the atomic mass of 1/12 of the mass of a carbon-12 atom. Since both quantities in the ratio are masses, the resulting value is dimensionless; hence the value is said to be relative and does not have a unit.

<em>Note that the relative atomic mass of atoms is not always a whole number because of it being isotopic in nature.</em>

  • <em>Divide each abundance by 100 then multiply by atomic mass</em>
  • <em>Do that for each isotope, then add the two result. Thus</em>

Relative atomic mass of Boron = (18.5/100 x 11) + (81/100 x 10)

                                                 = 2.035 + 8.1

                                                 = 10.135

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The equilibrium constant for the chemical equation is Kp = 5.23 at 191 °C. Calculate the value of the Kc for the reaction at 191
Lapatulllka [165]
To convert from Kp to Kc, you need this formula---> Kp= Kc (RT)^Δn, where Δn= gas moles of product- gas moles of reactants. since you did not give a reaction formula, I can't calculate Δn. but all once you find it out. just plug it. 

Kp= Kc (RT)^Δn------------------> Kc= Kp/[(RT)^Δn]
 Kp= 5.23
R= 0.0821
T= 191 C= 464 K
Δn= ?

Kc= 5.23/ (0.0821 x 464)^Δn= ???

7 0
3 years ago
Mixtures of benzene and cyclohexane exhibit ideal behavior. A solution was created containing 1.5 moles of liquid benzene and 2.
goblinko [34]

Answer:

Vapour pressure of cyclohexane at 50°C is 490torr

Vapour pressure of benzene at 50°C is 90torr

Explanation:

Using Raoult's law, pressure of a solution is defined by the sum of the product sbetween mole fraction of both solvents and pressure of pure solvents.

P_{solution} = X_{A}P^0_{A}+X_{B}P^0_{B}

In the first solution:

X_{cyclohexane}=\frac{2.5mol}{2.5mol+1.5mol} =0.625

X_{benzene}=\frac{1.5mol}{2.5mol+1.5mol} =0.375

340torr = 0.625P^0_{A}+0.375P^0_{B} <em>(1)</em>

For the second equation:

X_{cyclohexane}=\frac{3.5mol}{3.5mol+1.5mol} =0.700

X_{benzene}=\frac{1.5mol}{3.5mol+1.5mol} =0.300

370torr = 0.700P^0_{A}+0.300P^0_{B}<em>(2)</em>

Replacing (2) in (1):

340torr = 0.625P^0_{A}+0.375(1233.3-2.333P^0_{A})

340torr = 0.625P^0_{A}+462.5-0.875P^0_{A}

-122.5torr = -0.250P°A

P^0_{A} = 490 torr

<em>Vapour pressure of cyclohexane at 50°C is 490torr</em>

And for benzene:

370torr = 0.700*490torr+0.300P^0_{B}

P^0_{B}=90torr

<em>Vapour pressure of benzene at 50°C is 90torr</em>

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3 years ago
Identify the cfc with the shortest atmospheric lifetime
goldenfox [79]
CFC-11 is typically the CFC with the shortest atmospheric lifetime. 
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3 years ago
How do you classify a metal
Alenkinab [10]

Answer:

They are solid (with the exception of mercury, Hg, a liquid).

They are shiny, good conductors of electricity and heat.

They are ductile (they can be drawn into thin wires).

They are malleable (they can be easily hammered into very thin sheets).

If this satisfies you please consider giving me brainliest :)

8 0
3 years ago
Please help me ASAP the question is done below
mixas84 [53]

Answer:

Explanation:

First Question. Answer is: B. They are different.

For examle, balanced chemical reaction of forming water from hydrogen and oxygen:

2H₂ + O₂ → 2H₂O.

During chemical reaction no particles are created or destroyed, the atoms are simply rearranged from the reactants to the products.

Oxygen (element) has boiling point of -183°C and hydrogen has boiling point of -253°C. In this chemical change water (compound) is produced and it has new boiling point, boiling point of water is 100°C.

6 0
3 years ago
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