All categories

2 years ago

A solution was prepared by mixing 50.0 g

Chemistry

1 answer:

frez [133]2 years ago

4 0

Answer:

4.78 %.

Explanation:

<em>mass percent is the ratio of the mass of the solute to the mass of the solution multiplied by 100.</em>

<em>mass % = (mass of solute/mass of solution) x 100.</em>

mass of MgSO₄ = 50.0 g,

mass of water = d.V = (0.997 g/mL)(1000.0 mL) = 997.0 g.

mass of the solution = mass of water + mass of MgSO₄ = 997.0 g + 50.0 g = 1047.0 g.

<em>∴ mass % = (mass of solute/mass of solution) x 100</em> = (50.0 g/1047.0 g) x 100 = <em>4.776 % ≅ 4.78 %.</em>

You might be interested in

A given sample of caffeine, C8H10N4O2, has 6.47 x 1022

Verdich [7]

Answer:

<u>8.08 × </u> $10^{22}$ <u> atoms of hydrogen</u>

Explanation:

From the given data, we have two categories of variables (unknowns):

Amount (moles or mass) of Caffeine
Amount (moles or mass) of Hydrogen

The longer route would be to solve for these variables first, by determining the number of moles of the Caffeine sample (0.134 moles of C8H10N4O2) from the mass of carbon (12.89 g = 1.07 moles in 6.47 $10^{22}$ atoms) provided. And then solve for the number of atoms of H. <u><em>[N.B: 1 mole of ANY substance = 6.022 × </em></u> $10^{22}$ <u><em> atoms ]</em></u>

Alternatively and quicker, we can use the mole ratios of the Carbon:Hydrogen atoms in the compound.

8 : 10 ≡ 4 : 5

If 4 moles -- 6.47 $10^{22}$ atoms

Then 5 moles -- ?? atoms

⇒ No. of atoms of Hydrogen = $\frac{5*6.47*10^{22}}{4}$

<u>=8.08 × </u> $10^{22}$ <u> atoms of hydrogen</u>

3 0

2 years ago

A mixture of sand and table salt cam be separated by filtration because the substances in the mixture differ in

Stels [109]

A mixture of sand and table salt can be separated by filtration because the substances in the mixture differ in solubility. Because sand and table salt have a different ability to dissolve they can easily be separated. What can be done to separate this mixture is to add water to it and stir it thoroughly. The salt will easily dissolve in water while the sand will stay insoluble. The filtration of this mixture will result in salt being drained off with water while only the sand will remain.

6 0

2 years ago

Excess aqueous copper(II) nitrate reacts with aqueous sodium sulfide to produce aqueous sodium nitrate and copper(II) sulfide as

nikitadnepr [17]

The question in incomplete, complete question is;

Determine the theoretical yield:

Excess aqueous copper(II) nitrate reacts with aqueous sodium sulfide to produce aqueous sodium nitrate and copper(II) sulfide as a precipitate. In this reaction 469 grams of copper(II) nitrate were combined with 156 grams of sodium sulfide to produce 272 grams of sodium nitrate.

Answer:

The theoretical yield of sodium nitrate is 340 grams.

Explanation:

$Cu(NO_3)_2(aq)+Na_2S(aq)\rightarrow 2NaNO_3(aq)+CuS(s)$

Moles of copper(II) nitrate = $\frac{469 g}{187.5 g/mol}=2.5013 mol$

Moles of sodium sulfide = $\frac{156 g}{78 g/mol}=2 mol$

According to reaction, 1 mole of copper (II) nitrate reacts with 1 mole of sodium sulfide.

Then 2 moles of sodium sulfide will react with:

$\frac{1}{1}\times 2mol= 2 mol$ of copper (II) nitrate

As we can see from this sodium sulfide is present in limiting amount, so the amount of sodium nitrate will depend upon moles of sodium sulfide.

According to reaction, 1 mole of sodium sulfide gives 2 mole of sodium nitrate, then 2 mole of sodium sulfide will give:

$\frac{2}{1}\times 2mol=4 mol$ sodium nitrate

Mass of 4 moles of sodium nitrate :

85 g/mol × 4 mol = 340 g

Theoretical yield of sodium nitrate = 340 g

The theoretical yield of sodium nitrate is 340 grams.

7 0

2 years ago

Read 2 more answers

An enzyme with molecular weight of 310 kDa undergoes a change in shape when the substrate binds. This change can be characterize

oee [108]

Answer:

(a) r = 6.26 * 10⁻⁷cm

(b) r₂ = 6.05 * 10⁻⁷cm

Explanation:

Using the sedimentation coefficient formula;

s = M(1-Vρ) / Nf ; where s is sedimentation coefficient, M is molecular weight, V is specific volume of protein, p is density of the solvent, N is Avogadro number, f if frictional force = 6πnr, n is viscosity of the medium, r is radius of particle

s = M ( 1 - Vρ) / N*6πnr

making r sbjct of formula, r = M (1 - Vρ) / N*6πnrs

Note: S = 10⁻¹³ sec, 1 KDalton = 1 *10³ g/mol, I cP = 0.01 g/cm/s

r = {(3.1 * 10⁵ g/mol)(1 - (0.732 cm³/g)(1 g/cm³)} / { (6.02 * 10²³)(6π)(0.01 g/cm/s)(11.7 * 10⁻¹³ sec)

r = 6.26 * 10⁻⁷cm

b. Using the formula r₂/r₁ = s₁/s₂

s₂ = 0.035 + 1s₁ = 1.035s₁

making r₂ subject of formula; r₂ = (s₁ * r₁) / s₂ = (s₁ * r₁) / 1.035s₁

r₂ = 6.3 * 10⁻⁷cm / 1.035

r₂ = 6.05 * 10⁻⁷cm

8 0

2 years ago

In thionyl chloride, cl2so (s is the central atom), the formal charge on sulfur and number of lone pairs on sulfur are, respecti

zimovet [89]

Sulfur in the thionyl compound will have the formal charge or +1 and has two lone electrons or one lone pair.

<h2>Further Explanation</h2><h3>Lewis Structures</h3>

In order to determine the formal charge and number of lone pairs, it is imperative to draw the Lewis structure first. The steps in drawing the lone pairs are:

Get the total number of valence electrons by adding the number of valence electrons of each atom in the compound.
Determine the central atom.
Place the other atoms around the central atom and connect each to the central atom by a single bond. For every single bond, 2 electrons from the total valence electrons are shared.
Distribute the remaining valence electrons to the terminal atoms. Start by distributing to one terminal atom until the atom has an octet then move to the next terminal atom. If all terminal atoms have an octet, the remaining electrons will be placed in the central atom.

For thionyl chloride, the central atom is sulfur and the total number of valence electrons is:

Cl = 7 × 2 = 14

S = 6

O = 6

Total Valence Electrons = 14 + 6 + 6 = 26 electrons. Following the steps above, the resulting Lewis structure is shown in the attachment.

Once the Lewis structure is known, the number of lone pairs in the central atom can be known. For thionyl chloride, it can be seen that there are two unshared electrons in S. Therefore, S has one lone pair.

<h3>Formal Charges</h3>

The relative distribution of electrons in a molecule can be described through the formal charges of each atom. The formal charge describes how many electrons there are in an atom compared to how many electrons it has if it were not bonded. For a molecule to have a stable structure, the formal charges of all the atoms must be at the lowest possible values.

The formula to determine the formal charge is:

Formal Charge = # valence electron for the isolated atom - (# bonds + non-bonding electrons)

For the thionyl compound, the formal charge of S is determined using the following equation and by looking at the Lewis Structure:

Valence Electrons of a Sulfur atom = 6
Number of bonds around Sulfur = 3
Number of non-bonding electrons on Sulfur = 2

Formal Charge of S = 6 - (3+2)

Formal Charge of S = +1

This means that sulfur has less electrons around it in the molecule than it has as an isolated atom.

<h3>Learn More</h3>

Lewis Structure brainly.com/question/2323095
Valence Electrons brainly.com/question/2376134

<em>Keywords: formal charge, lone pairs</em>

5 0

2 years ago

Read 2 more answers