What is the density of an object with a mass with a mass of 60 g and a volume of 2 cm 3 ?

What are miscible liquids?

sasho [114]

Answer:

ones that can be mixed together

Explanation:

like water or ethanol

7 0

3 years ago

Read 2 more answers

1. The equation for the reaction between zinc and aqueous copper(II) sulfate is shown.

Fed [463]

Answer:

The oxidation state of the reducing agent has changed from 0 to +2.

Explanation:

reducing agent is anything that loses electron or gains oxygen

in this case, zinc

3 0

3 years ago

Read the given equation. 2Na + 2H2O ? 2NaOH + H2 During a laboratory experiment, a certain quantity of sodium metal reacted with

emmasim [6.3K]

Answer:

The number of moles of Na metal that used initially = 0.70 mol.

The quantity of Na metal used initially to produce 7.80 of H₂ gas = 16.02 g.

Explanation:

It is a stichiometry problem.

The balanced equation shows that <em>2.0 moles of Na metal </em>react with 2.0 moles of water to produce 2.0 moles of NaOH and <em>1.0 mole of H₂</em>,

Firstly, we need to convert the volume of H₂ (7.80 L) produced to no. of moles (n) using the ideal gas law: <em>PV = nRT</em>,

where, P is the pressure of the gas in atm<em> (P at STP = 1.0 atm)</em>,

V is the volume of the gas in L <em>(V = 7.80 L)</em>,

n is the number of moles in mole,

R is the general gas constant<em> (R = 0.082 L.atm/mol)</em>,

T is the temperature of the gas in K <em>(T at STP = 0.0 °C + 273 = 273.0 K)</em>.

∴ The number of moles of H₂ gas (n) = PV / RT = [(1.0 atm)(7.80 L)] / [(0.082 L.atm/mol.K)(273.0 K)] = 0.35 mol.

<em>Using cross multiplication:</em>

2.0 moles of Na will produce → 1.0 mole of H₂, from the stichiometrey.

??? moles of Na will produce → 0.35 mole of H₂.

∴ The number of moles of Na metal that used initially = (2.0 mol)(0.35 mol) / (1.0 mol) = 0.70 mol.

Now, we can get the quantity of Na metal using the relation:

∴ mass = n x molar mass = (0.70 mol)(22.989 g/mol) = 16.02 g.

6 0

3 years ago

Name two compounds with more exothermic lattice energies than scandium oxide and justify your choice.

N76 [4]

Answer:

1 . $Al_2O_3$

2. $TiO_2$

Explanation:

The more stable the ionic compound, the more is it lattice energy.

The more the charge on the cation and the anion, the greater is the lattice energy.
The less the size of the cation and the anion, the greater is the lattice energy.

Scandium oxide ( $Sc_2O_3$ ) is an oxide in which $Sc^{3+}$ behaves as cation and $O^{2-}$ behaves as anion.

The compounds which has higher lattice energy than scandium oxide are:

1 . $Al_2O_3$

This is because the charge are same on the cation and the anion as in the case of the Scandium oxide but the size of the cation $Al^{3+}$ is smaller than $Sc^{3+}$ . Thus, this corresponds to higher lattice energy.

2. $TiO_2$

This is because the charge on the cation $Ti^{4+}$ is greater than that of $Sc^{3+}$ and also the size of the cation $Ti^{4+}$ is smaller than $Sc^{3+}$ . Thus, this corresponds to higher lattice energy.

3 0

3 years ago

1. Which of the following pairs of factors affects the solubility of a particular substance? (1 point)

Lina20 [59]

<h2>Question no 1:</h2><h3>Answer:</h3>

The correct answer is option A which is temperature and the nature of solute and solvent

<h3>Explanation:</h3>

The solubility of a substance is its ability to dissolve in a particular solution.
Solubility is highly dependent on the temperature and nature of solute and solvent.
It is directly proportional to the temperature. As we increase the temperature, the solubility of substantial increases but for the exothermic reactions, solubility is inversely proportional to temperature.
Solubility is absolutely dependent on the nature of solute and solvent, as polar solute and solvents have high solubility than non polar.

<h2>Question no. 2</h2><h3>Answer:</h3>

The correct answer is option B which is a large amount of solute.

<h3>Explanation:</h3>

A concentrated solution contains the maximum amount of solute which can be dissolved in the solvent.
For example, in water sugar solution concentrated solution will contain a large amount of sugar dissolved in water without the addition of heat.
In dilute solution, there is a small amount of solute.

<h2>Question no. 3:</h2><h3>Answer:</h3>

The correct answer is option B which is molarity × liters of solution.

<h3>Explanation:</h3>

Molarity of a solution is the total number of moles of solute per unit volume of solution.

Its formula is:

Molarity = Number of moles of the solute/volume of solution in liters.

A number of moles of solute = Molarity × Volume of the solution.

So the number of moles of solute is equal to the molarity and volume of solution. Hence correct option is B.

<h2>Question no 4.</h2><h3>Answer:</h3>

The correct answer is option D. Molarity of the dilute solution = 0.81 M

<h3>Explanation:</h3>

Given data:

initial volume = V1 = 225 mL = 0.225 L

Initial molarity = M1 = 0.80M

Final volume = V2 = 1 L

Final molarity = M2 = ?

Solution:

It is the dilution of the stock solution and the formula is given below:

V1M1 = V2M2

M2 = V1.M1/V2

By putting values in the formula:

M2 = 0.225 × 0.8/1

M2= 0.18

So the final molarity of the solution will be 0.18 M. Hence the correct answer is option D.

<h2>Question no. 5</h2><h3>Answer:</h3>

The correct answer is option B which is supersaturation.

<h3>Explanation:</h3>

Colligative properties of the solution are the properties which are not dependent on the number of particles of the solute in the solution.
While supersaturation of the solution means the solution containing the highest number of solute particles dissolved in the solution.
Since supersaturation is dependent on a number of solutes, it is not a colligative property.

<h2>Question no 6.</h2><h3>Answer:</h3>

The correct answer is option B/C, "which disrupts crystal formation of the solvent".

<h3>Explanation:</h3>

Depression of freezing point is the colligative property of the solution.
Which the lowering of the freezing point of a solution by adding the solute.
The addition of solute disrupts the crystal formation in the solvent, as it disrupts the intermolecular forces between solute particles.
Hence option B and C are the correct options because both have the same statement.

<h2>Question no 7.</h2><h3>Answer:</h3>

The correct answer is option D which is 142.

<h3>Explanation:</h3>

<u>Given data:</u>

Volume of solution = 167 ml

Percentage of solution = 85%

The volume of alcohol =?

<u>Solution:</u>

Percentage of solution ( v/v) = volume of solute/volume of solution × 100

The volume of solute = percentage × volume of solution/100

By putting values in above formula:

Volume of alcohol = 85 × 167/100 = 141.95 ml

<em><u>Hence the correct answer is option D which is approximately 142(141.95).</u></em>

8 0

3 years ago

Read 2 more answers