Which of the statements below about buoyancy is true?

what did ernest rutherford’s gold foil experiment demonstrate about atoms? their positive charge is located in a small region th

Crank

The gold foil experiment by Ernest Rutherford proved that the positive charge of an atom is located in the nucleus, the small region that contributes most to the mass of the atom. Most of the atom is empty space, but the nucleus, however small, dictates the mass of the atom.

7 0

3 years ago

When iron (II) hydroxide is mixed with phosphoric acid, iron (II) phosphate precipitate results.

Triss [41]

Answer:

a. Fe(OH)2

b. H3PO4

c. 0.01185 moles

Explanation:

The balanced equation of the question will be:

3 Fe(OH)2 + 2 H3PO4 → Fe3(PO4)2 + 6 H2O

a. what is the limiting reactant?

A limiting reactant is a reactant that will be used up in the reaction. We can find it by calculating the stoichiometric ratio. The reactant with the lowest ratio, which will be depleted first, is the limiting reactant. The reaction will stop if any reactant depleted, so the limiting reactant will be the one that determines how many products made. If you add more of a limiting reactant, the reaction will continue.

The molecular mass of Fe(OH)2 is 90g/mol while the molecular mass of H3PO4 is 98 g/mol. The number of each reactant in moles will be

Fe(OH)2 = 3.20g/ (90g/mol) =0.03555 mol

H3PO4 = 2.50g/ (98g/mol) = 0.02551 mol

The actual ratio of Fe(OH)2 : H3PO4 will be:

0.03555 mol/ 0.02551 mol= 1.393 mol/ 1 mol

The stoichiometric coefficient of Fe(OH)2 is 3 while H3PO4 is 2. Mean you need 3 moles Fe(OH)2 of to for the reaction every 2 moles of H3PO4.

The stoichiometric ratio will be: 3 mol/ 2 mol= 1.5 mol/ 1 mol

Since the actual ratio (1.393) is lower than the stoichiometric ratio(1.5) that means we have less Fe(OH)2 than H3PO4, thus the limiting reactant is the Fe(OH)2.

b. What is the reactant in excess?

The excess reactant is the reactant that will have to remain after the reaction stop. It's the opposite of the limiting reactant. Since we still have remains, adding excess reactant won't continue the reaction.

We already know that Fe(OH)2 is the limiting reactant, then H3PO4 will be the excess reactant. The number of reactant remaining will be:0.02551 mol -0.03555 mol/ (1.5 mol -1 mol)=0.00181 mol

c. What is the theoretical yield

Theoretical yield is the predicted amount of product made if the reaction happens with a 100% yield. To find the yield, we need to know how much reactant used and then multiply it with the stoichiometric coefficient of the product. If Fe(OH)2 the limiting reactant then it means all 0.03555 mol of it will be used. The amount of iron (iii) phosphate made will be:

0.03555 mol * 1/3= 0.01185 moles

3 0

4 years ago

The hydrogen atomic emission spectrum includes a UV line with a wavelength of 92.3 nm.

EastWind [94]

To answer the first question we can say that that line is associated with a transtition between an excited state and the ground state. We can explain this <span>transitions in the Lyman series, which appear in the UV region of the spectrum and all terminate at the ground electronic state of the hydrogen atom. Now for the second question I have always known that the value of n1 of this transition is 1. And the wavelenght of the longest wavelenght photon that a ground state hydrogen can absorb is 121.5 nm</span>

5 0

3 years ago

q6- convert the fisher projection of the following amino acid into a line structure. label the chiral center on the line structu

Vera_Pavlovna [14]

Fisher projection is the representation of organic molecule in2-D without destroying the3-D stereochemical information.

<h3>What does a Fischer projection in organic chemistry mean?</h3>

A Fischer projection is a drawing technique used in organic chemistry to depict molecules in two dimensions while maintaining the three-dimensional stereochemical information regarding the absolute arrangement at chiral centers.

<h3>What sets the Fischer projection apart from the Haworth projection?</h3>

In contrast to Fischer projections, which are used to represent sugars in their open-chain form, Haworth projections are typically employed to represent sugars in their cyclic forms.

To know more about Fisher projection visit:

brainly.com/question/13265192

#SPJ4

5 0

1 year ago

A solution of iron(III) chlorate was poured into a lithium phosphate solution. Would you expect a precipitate to form if 354.0 m

Artist 52 [7]

Answer:

K. Yes, because Qsp > Ksp for iron(III) phosphate

Explanation:

Lithium chlorate is very soluble in water, that means has a big ksp.

Iron (III) phosphate has a ksp of 1.3x10⁻²²

Ksp formula of iron (III) phospate is:

FePO₄(s) ⇄ Fe³⁺(aq) + PO³⁻(aq)

Ksp = [Fe³⁺] [PO₄³⁻] = 1.3x10⁻²²

Molar concentration of Fe³⁺ and PO₄³⁻ is:

[Fe³⁺] = 0.340L ₓ (2.52x10⁻⁹mol / L) ÷ (0.354L + 0.520L) = <em>9.8x10⁻¹⁰M</em>

[PO₄³⁻] = 0.520L ₓ (4.65x10⁻¹¹mol / L) ÷ (0.354L + 0.520L) = 2.78<em>x10⁻¹¹M</em>

Replacing in Ksp formula:

Qsp = [9.8x10⁻¹⁰] [2.78x10⁻¹¹M] = 2.72x10⁻²⁰

As Qsp > Kps, the equlibrium will shift to the right decreasing the ions concentrations producing FePO₄(s), <em>a precipitate</em>

<em>The ions decreases its concentration until Q = Kps</em>

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Thus, right answer is:

<em>K. Yes, because Qsp > Ksp for iron(III) phosphate </em>

6 0

3 years ago