can someone show me the work on 3-8?

Answer:

1.55 x 10²⁴ formula units

Explanation:

Given parameters:

Number of moles of CaCl₂   = 2.58moles

Unknown:

Formula units in the compound  = ?

Solution:

To solve this problem, we must understand that;

    1 mole of a substance contains 6.02 x 10²³ formula units

   2.58 moles will contain 2.58 x  6.02 x 10²³ formula units  

                                            = 1.55 x 10²⁴ formula units

Answer:

36

orrr

20

Explanation:

36 explanation:18x2=36

20 explanation:18+2=20

The volume of the object : 9 ml

Given

The density of an object : 2 g/ml

Mass : 18 g

Required

The volume

Solution

Density is a quantity derived from the mass and volume  

Density is the ratio of mass per unit volume  

Density formula:  

[tex]\large {\boxed {\bold {\rho ~ = ~ \frac {m} {V}}}}[/tex]

ρ = density  

m = mass  

v = volume

V=m : ρ

V = 18 g : 2 g/ml

V = 9 ml

Answer:

Radio wave

Explanation:

Radio waves are a type of electromagnetic wave radiation with wavelengths in the electromagnetic spectrum longer than infrared light

A seismic wave is an elastic wave generated by an impulse such as an earthquake or an explosion.

Sound and water waves are mechanical waves; meaning, they require a medium to travel through.

Answer:

[OH⁻] = 3.34x10⁻³M; Percent ionization = 0.54%; pH = 11.52

Explanation:

Kb of the reaction:

NH3 + H2O(l) ⇄ NH4+ + OH-

Is:

Kb = 1.8x10⁻⁵ = [NH₄⁺] [OH⁻] / [NH₃]

As all NH₄⁺ and OH⁻ comes from the same source we can write:

[NH₄⁺] = [OH⁻] = X

And as [NH₃] = 0.619M

1.8x10⁻⁵ = [X] [X] / [0.619M]

1.11x10⁻⁵ = X²

3.34x10⁻³ = X = [NH₄⁺] = [OH⁻]

% ionization:

[NH₄⁺] / [NH₃] * 100 = 3.34x10⁻³M / 0.619M * 100 = 0.54%

pH:

As pOH = -log [OH-]

pOH = 2.48

pH = 14 - pOH

Answer:

See explanation

Explanation:

The reaction between alcohol and acidified potassium dichromate  is a redox reaction. This reaction can be used to detect a drunken driver.

Alcohols can be oxidized to aldehydes, ketones and carboxylic acids depending on the structure of the alcohol. Primary alcohols yield adehydes and carboxylic acids while secondary alcohols are oxidized to ketones.

The colour of the acidified potassium dichromate turns from orange to green when exposed to alcohols from the breath of a drunken driver.

Answer:

A closed container is the best way to measure the volume of a liquid

Answer:

fe

Explanation:

forms one binary compounds with chlorine

Answer:just for the ponits

Explanation:ima be a jenna

Answer:

Cosmetics

Explanation:

The products of chemical industries that are sued to care for the skin and make people more attractive are cosmetics.

Cosmetics are chemical products used for beauty enhancement.

Answer:

thunderstorm

Explanation: The cumulus stage is the first stage in a thunderstorm and it involves clouds forming. We see the cloud that will become a thunderstorm as it is starting to form and grow. This is due to the rising levels of thermal energy.

Answer:

C) hydrogen bonds

Explanation:

The abnormally high boiling point of HF compared to HCl is primarily due to the intermolecular forces called hydrogen bonds.

Hydrogen bonds are intermolecular forces of attraction between polar molecules in which a hydrogen atom is directly joined to a highly electronegative atom (oxygen, nitrogen or fluorine).

Hydrogen bonds are very strong force of attraction compared to dipole - dipole attraction that holds the HCl together.

Answer:

+ 3

Ex planation:

Al3+ indicates an ion of aluminum having a charge of + 3. I.e., since an aluminum atom normally has 13 protons and 13 electrons, this ion has 10 electrons (-10 charge) and 13 protons (+ 13 charge) giving it a charge of + 3 (-10 + 13 = +3).

hope this helps!

Answer: The correct option is A ( Break the crackers into pieces.)

Explanation:

The rate of reaction between two substances can be affected by the following factors:

--> surface area of reacting substances

--> concentration

--> reaction mechanism

--> temperature

--> the presence of a catalyst and

--> pressure ( if gaseous)

Reagents in solution tend to react faster than reagents in solid form. This is because molecules are freer to move about and collide more effectively in solutions. For example, a lump of zinc will not react as fast as powdered zinc with dilute hydrochloric acid to produce hydrogen. This is the same with the reaction between the crackers and soup. To increase the reaction of the substances, the crackers needs to be broken into pieces(thus,increased surface area)

Answer:

Glucose

Explanation:

Glucose is broken down into water and carbon dioxide.

hope this helps! :)

Answer:

The electron spends a lot of time away from hydrogen and hydrogen's nucleus is exposed for

interaction

Explanation:

I got the question right

During hydrogen bonding, The electron of hydrogen spends a lot of time away from hydrogen and hydrogen's nucleus is exposed for interaction. Option C is correct.

The presence of hydrogen atoms bound to strongly electronegative elements like nitrogen, oxygen, or fluorine as well as the polarity of the molecule determine whether hydrogen bonds are present in the molecule.

The electron density in the bond between a hydrogen atom and one of these electronegative atoms shifts in favor of the electronegative atom, giving rise to a partial positive charge on the hydrogen atom and a partial negative charge on the electronegative atom. Therefore, the hydrogen atoms in one molecule can establish hydrogen bonds with the electronegative atoms in other molecules.

To know more about hydrogen bonding here

brainly.com/question/17659933

#SPJ2

The question should be

What happens to hydrogen during hydrogen bonding?

a)The proton spends a lot of time away from hydrogen and hydrogen's electron is exposed for interaction

b)The electron spends a lot of time away from hydrogen and hydrogen's electron is exposed for interaction

c)The electron spends a lot of time away from hydrogen and hydrogen's nucleus is exposed for interaction

d) The proton spends a lot of time away from hydrogen and hydrogen's nucleus is exposed for interaction

Answer:

Tyra can make 53 batches

Explanation:

Given

[tex]Batches = \frac{1223}{r}[/tex]

Required

Find the number of batches when r = 23

To do this, we simply substitute 23 for r in [tex]Batches = \frac{1223}{r}[/tex]

So, we have:

[tex]Batches = \frac{1223}{23}[/tex]

[tex]Batches = 53.17[/tex]

Approximate:

[tex]Batches = 53[/tex]

Answer:

C. Niche

Explanation:

The role of an organism in it's habitat is it's niche.

Answer:

The answer is chlorine

Explanation:

Answer:

68.6 °C

Explanation:

From conservation of energy, the heat lost by acetone, Q = heat gained by aluminum, Q'

Q = Q'

Q = mL where Q = latent heat of vaporization of acetone, m = mass of acetone = 3.33 g and L = specific latent heat of vaporization of acetone = 518 J/g

Q' = m'c(θ₂ - θ₁) where m' = mass of aluminum = 44.0 g, c = specific heat capacity of aluminum = 0.9 J/g°C, θ₁ = initial temperature of aluminum = 25°C and θ₂ = final temperature of aluminum = unknown

So, mL = m'c(θ₂ - θ₁)

θ₂ - θ₁ = mL/m'c

θ₂ = mL/m'c + θ₁

substituting the values of the variables into the equation, we have

θ₂ = 3.33 g × 518 J/g/(44.0 g × 0.9 J/g°C) + 25 °C

θ₂ = 1724.94 J/(39.6 J/°C) + 25 °C

θ₂ = 43.56 °C + 25 °C

θ₂ = 68.56 °C

θ₂ ≅ 68.6 °C

So, the final temperature (in °C) of the metal block is 68.6 °C.

The final temperature of the metal block is 74.97°C

The specific heat of a substance is the required quantity of heat needed to raise the temperature of 1 gram of the substance by 1° C.

From the parameters given:

The number of moles of acetone is:

[tex]\mathbf{= 3.33 g \times \dfrac{mol}{58.08 \ mol}}[/tex]

= 0.0573 mol

At standard conditions, the heat of vaporization of acetone is:

[tex]\mathbf{\Delta H = 32.0 \ kJ/mol \times 0.0578 \ mol } \\ \\ \mathbf{\Delta H = 1.8496 \ kJ } \\ \\ \mathbf{ \Delta H = 1.85 \times 10^3 \ J}[/tex]

Given that:

The specific heat of the aluminum is = 0.903 J/g° C

The heat energy can be computed as:

q = msΔT

q = 41 g × 0.903 J/g° C × (x - 25°C)

Using the calorimetry principle, heat energy lost by metal = heat energy gained by acetone.

i.e.

[tex]\mathbf{q_{(acetone)} gain = q_{(metal)} lost }[/tex]

[tex]\mathbf{-1.85 \times 10^3 \ J = - 41 g \times 0.903 \ J/g^0 C \times ( x - 25^0 c) }[/tex]

[tex]\mathbf{1.85 \times 10^3 \ J = 41 g \times 0.903 \ J/g^0 C \times ( x - 25^0 c) }[/tex]

[tex]\mathbf{(x - 25 ^0 C) = \dfrac{1.85 \times 10^3 \ J }{ 41 g \times 0.903 \ J/g^0 C}}[/tex]

[tex]\mathbf{(x - 25 ^0 C) = 49.97^0 C}}[/tex]

[tex]\mathbf{x = 49.97^0 C+25 ^0 C}}[/tex]

x = 74.97 °C

Learn more about specific heat here:

https://brainly.com/question/1430612

Answer:

3012.51×10²³ atoms of Ne

Explanation:

Given data:

Mass of Ne = 10090 g

Number of atoms = ?

Solution;

Formula:

Number of moles = mass/ molar mass

Molar mass of Ne = 20.17 g/mol

Number of moles = 10090 g/ 20.17 g/mol

Number of moles = 500.25 mol

Number of atoms:

1 mole contain 6.022×10²³ atoms

500.25 mol × 6.022×10²³ atoms / 1 mol

3012.51×10²³ atoms

Answer:

All except a diamond

Explanation:

The helium in the balloon has mass it fills the space its in.

The neon-filled tube has mass because it takes up space.

Water in a glass has mass because the water is taking up space.

A diamond does not because it does not take up space.

Answer:

1.9g of F₂ were consumed in the reaction

Explanation:

Based on the chemical reaction:

2NaCl + F₂ →  2 NaF + Cl₂

Where 2 moles of NaCl react per mole of F₂ to produce 2 moles of NaF and 1 mole of Cl₂

To understand in a better way how the reaction occurs we need to convert each mass of compound to moles:

Moles of NaCl -Molar mass: 58.44g/mol-:

5.4g * (1mol / 58.44g) = 0.092 moles NaCl

Moles of NaF -Molar mass: 41.988g/mol-:

4.9g * (1mol / 41.998g) = 0.12 moles NaF

Moles of Cl₂ -Molar mass: 70.90g/mol-:

3.7g * (1mol / 70.90g) = 0.052 moles Cl₂

That means approximately 0.1 moles of NaCl react with 0.05 moles of F₂ to produce 0.1moles of NaF and 0.05 moles of Cl₂.

0.05 moles of F₂ are:

0.05 moles * (38g/mol) =

Answer:

I think that the first one is right(A)

1.999 mol gas

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Step 1: Define

1.204 × 10²⁴ atoms gas

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 4 sig figs.

1.99934 mol gas ≈ 1.999 mol gas

Answer:

3.79 x 10²⁴atoms

Explanation:

Given parameters:

Number moles of lead  = 6.3moles

Unknown:

Number of atoms  = ?

Solution:

To solve this problem,

              1 mole of a substance contains  6.02 x 10²³ atoms

            6.3 mole of Pb  will contain 6.3  x 6.02 x 10²³ = 3.79 x 10²⁴atoms

Answer:

metric system

Explanation:

In the metric system, the basic unit of length is the meter. A meter is slightly larger than a yardstick, or just over three feet. The basic metric unit of mass is the gram. Finally, the basic metric unit of volume is the liter.