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3 years ago

Read the following passage.

Chemistry

2 answers:

tangare [24]3 years ago

8 0

Answer:

The correct answer is that yes all the scientific theories and their features contributes to the discovery of an atom.

Explanation:

In the beginning, Democritus gave the term atom, however, he gave the wrong theory regarding atom. The term atom is even used at the present time. Aristotle provided the right theory regarding the prevalence of atom. Then Dalton postulated various things in his atomic theory, in which some were accurate, while others were proved later wrong.

The accurate postulates of Dalton were also incorporated in J.J. Thomson theory of sub-atomic particles. Thus, all the theories associated with an atom provides to its discovery, irrespective of the fact that whether it is correct or wrong.

Archy [21]3 years ago

7 0

Answer is: the discovery of sub atomic particles like electrons.

J. J. Thomson discovered the electron in 1897.

His "plum pudding" model (1904) suggested: the electrons are embedded in the positive charge.

With this model, he abandoned his earlier hypothesis (the atom was composed of immaterial vortices).

J.J. Thomson placed two oppositely charged electric plates around the cathode ray. He did experiments using different metals as electrode materials and found that the properties of the cathode ray remained constant no matter what cathode material he used.

Tomson concluded that atoms are divisible and that the corpuscles are their building blocks (atoms are made up of smaller particles).

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In the reaction of 6 moles of CH4 with excess oxygen, how many moles of water could be produced? A. 4 B. 6 C. 8 D. 12

notsponge [240]

*brings you good news*

The answer is D. 12

Hope i will help you angain sometime :)

~~~~~SoraKeyblader~~~~~

8 0

3 years ago

Roman mixes 12 liters of 8% acid solution with a 20% acid solution, which results in a 16% acid solution. Find the number of lit

inysia [295]

Let the 8% solution be A, the 20% solution be B and the final solution be C.

C = A + B
C = 12 + B

0.16C = 0.08(12) + 0.2(B)
0.16(12 + B) = 0.96 + 0.2B
0.96 = 0.04B
B = 24 Liters

C = 12 + 24
C = 36 Liters

3 0

4 years ago

You are asked to prepare 500 mL 0.200 M acetate buffer at pH 5.00 using only pure acetic acid ( MW=60.05 g/mol, pKa=4.76), 3.00

Vilka [71]

Answer:

You need to weight 6,005 g of acetic acid

Explanation:

Using Henderson-Hasselbalch formula you will obtain:

5,00 = 4,76 +log₁₀ $\frac{[Ac^-]}{[Acac]}$

Where Ac⁻ is the salt of acetic acid (Acac).

Solving:

1,738 = $\frac{[Ac^-]}{[Acac]}$ (1)

Also, yo know that:

0,200 M = [Ac⁻] + [Acac] (2)

Replacing (2) in (1):

[Acac] = 0,0730 M.

Thus:

[Ac⁻] = 0,127 M

The moles of each compound are:

Acac = 0,0730 M × 0,500 L = 0,0365 mol

Ac⁻ = 0,127 M × 0,500 L = 0,0635 mol

To prepare these moles it is necessary to use:

Acac + NaOH → AcNa + H₂O

The initial moles of Acac must be:

0,0365 moles + 0,0635 moles = 0,100 moles

To obtain 0,0635 moles of Ac⁻ you need to take this quantity of NaOH moles.

Thus, to obtain a acetate buffer of 5,00 you need to add 0,100 moles of acetic acid and 0,0635 moles of NaOH because This NaOH will react with acetic acid producing 0,0635 moles of Ac⁻ and surplus 0,0365 moles of acetic acid.

Now, to obtain 0,100 moles of acetic acid from pure acetic acid:

0,100 moles × $\frac{60,05 g}{1 mol}$ = 6,005 g

You need to weight 6,005 g of acetic acid

I hope it helps!

7 0

4 years ago

For the reaction 2A(g) â B(g), the equilibrium constant is Kp = 0.76. A reaction mixture initially contains 4.0 atm of gas (PA =

timofeeve [1]

Answer: (a) The reaction mixture will proceed toward products.

Explanation:

Equilibrium constant is defined as the ratio of pressure of products to the pressure of reactants each raised to the power their stoichiometric ratios. It is expressed as $K_p$

K is the constant of a certain reaction when it is in equilibrium, while Q is the quotient of activities of products and reactants at any stage other than equilibrium of a reaction.

For the given chemical reaction:

$2A(g)\rightleftharpoons B(g)$