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Artyom0805 [142]
2 years ago
8

The model of the atom where the central core contains protons and neutrons surrounded by a cloud of electrons is best described

as A) The Bohr model of the atom. B) The modern model of the atom. C) The plum pudding model of the atom. D) The solar system model of the atom.
Chemistry
2 answers:
noname [10]2 years ago
6 0
The modern model of the atom B)
WITCHER [35]2 years ago
4 0
I am thinking the answer is B. I think this because Bohr had a model similar, but his was lacking the cloud of electrons. His just had electrons orbiting the nucleus. 
I hope this is right!<span />
You might be interested in
What are the empirical formulas of a) ethylene glycol, a radiator antifreeze, molecular formula C2H6O2 b) peroxodisulfuric acid,
Temka [501]
<h2>The answers are CH_3O and HSO_4</h2>

Explanation:

Given -

a) The molecular formula of ethylene glycol -

    C_2H_6O_2

∴ The empirical formula of ethylene glycol will be -

    CH_3O

Given -

b) The molecular formula of per-oxo-disulfuric acid (a compound used in bleaching agents) -

    H_2S_2O_8

∴ The empirical formula of per-oxo-disulfuric acid will be -

    HSO_4

Hence, the answers are CH_3O and HSO_4.

6 0
2 years ago
A. The measured pH of a 0.100 M HCl solution at 25 degrees Celsius is 1.092. From this information, calculate the activity coeff
ra1l [238]

Answer:

activity coefficient \mathbf{\gamma =0.809}

activity coefficient \mathbf{\gamma = 0.791}

The change in pH in part A = 0.092

The change in pH in part B =  0.102

Explanation:

From the given information:

pH of HCl solution = 1.092

Activity of the pH solution [a] = 10^{-1.092}

[a] = 0.0809 M

Recall that [a] = \gamma × C

where;

\gamma  = activity coefficient

C = concentration

Making the activity coefficient the subject of the formula, we have:

\gamma = \dfrac{[a]}{C}

\gamma = \dfrac{0.0809 \ M}{0.100  \ M}

\mathbf{\gamma =0.809}

B.

The pH of a solution of HCl and KCl = 2.102

[a] = 10^{-2.102}

[a] = 0.00791 M

activity coefficient \gamma = \dfrac{0.00791 \ M}{0.01 \ M}

\mathbf{\gamma = 0.791}

C. The change in pH in part A = 1.091 - 1.0 = 0.092

The change in pH in part B = 2.102 -2.00 = 0.102

3 0
2 years ago
In a two-step synthesis where the first reaction has a 55% yield and the second reaction has a 24% yield, the overall percent yi
nekit [7.7K]

Answer:

13,2 %.

Explanation:

Overall yield = 0.55 * 0.24

= 0.132

= 13,2 %.

7 0
2 years ago
2KOH+H2SO4=k2SO4+2H2O Is a balanced equation, displaying the combination of potassium hydroxide with sulfuric acid increase pota
Lerok [7]

Answer:

The number of moles of potassium hydroxide, KOH required to make 4 moles of K₂SO₄ is 8 moles of KOH

Explanation:

2KOH + H₂SO₄ → K₂SO₄ + 2H₂O

From the above reaction, we have 2 moles of KOH combining with 1 mole of H₂SO₄ to produce 1 mole of K₂SO₄  and 2 moles of H₂O.

Therefore the number of moles of potassium hydroxide that will be needed to make 4 moles of K₂SO₄ is;

8KOH + 4H₂SO₄ → 4K₂SO₄ + 8H₂O

8 moles of KOH is required to make 4 moles of K₂SO₄.

6 0
2 years ago
Oxalic acid is a diprotic acid. calculate the percent of oxalic acid (h2c2o4) in a solid given that a 0.7984-g sample of that so
vlada-n [284]
This method of quantitative determination of percent purity is titrimetric reactions. These reactions most commonly involve neutralization reactions between an acid and a base. Then, we look at the neutralization reaction:

H₂C₂O₄ + 2 NaOH ⇒ Na₂C₂O₄ + 2 H₂O

So, we do the stoichiometric calculations. The important data we should know is the molar mass of oxalic acid which is equal to 90 g/mol.

(0.2283 mol/L NaOH * 0.3798 L * 1 mol H₂C₂O₄/ 2mol NaOH * 90 g/mol H₂C₂O₄) ÷ 0.7984 g *100%
= 488%

This is impossible. The purity can't be more than 100%. Looking at our calculations and the balance reaction, all steps were done correctly. So, I think there is some typographical error in the given. The mass of the sample should be 7.984 g. Then, the answer would be 48.87% purity.
5 0
2 years ago
Read 2 more answers
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