Which kind of energy change occurs when a candle is burning

Answer:

d = 8.96 g/cm³

Explanation:

Given data:

Volume of sample = 10.0 cm³

Mass of copper = 89.6 g

Density of copper = ?

Solution:

Formula:

d = m/v

d = density

m = mass

v = volume

by putting values,

d = 89.6 g/ 10.0 cm³

d = 8.96 g/cm³

Answer:

H₂O₂

Explanation:

Hydrogen peroxide is a typical example of a compound molecule. A compound is made up of one or more atoms that are combined together in a definite grouping.

The properties of a compound is different from those of the elements that combines to from them.

Answer:

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

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: [tex]Co+2Na_2S\rightarrow 4Na+CoS_2[/tex]

Explanation:

According to law of conservation of mass, mass can neither be created nor be destroyed. The atoms on the reactant side must be equal to the number of atoms on the product side so that the mass remains the same on reactant and product side. Thus the reactions are balanced.

Single displacement reaction is one where a more reactive element replaces the lesser reactive one.

The balanced chemical reaction will be:

[tex]Co+2Na_2S\rightarrow 4Na+CoS_2[/tex]

Answer:

Mass = 29.23 g

Explanation:

Given data:

Volume of solution = 814.2 mL 814.2/1000 = 0.8142 L)

Molarity of solution = 0.227 M

Mass of solute in gram = ?

Solution:

Molarity = number of moles / volume in L

By putting values,

0.227 M = number of moles / 0.8142 L

Number of moles = 0.227 M × 0.8142 L

Number of moles = 0.184 mol

Mass in gram:

Mass = number of moles × molar mass

Molar mass of calcium acetate = 158.17 g/mol

Mass = 0.184 mol × 158.17 g/mol

Mass = 29.23 g

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:

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:

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:

90.1km/hr

Explanation:

Given parameters:

Distance  = 30km

Time  = 20s  = 0.33hr

Unknown :

Speed of the car  = ?

Solution:

To solve this problem;

     Speed  = [tex]\frac{distance }{time}[/tex]  

Now insert the parameters and solve;

 Speed  = [tex]\frac{30}{0.333}[/tex]   = 90.1km/hr

Answer:

D. The nucleus occupies very little of the volume but contains most of its mass

Explanation:

Density is an intensive property as it does not depend on the quantity of the substances Whereas mass and volume are extensive property. Therefore,  the nucleus occupies very little of the volume but contains most of its mass. The correct option is option D.

Density tells about the compactness of the substances, how much dense is the substances in other words. Object that is more denser than water they just sink in the water.

Mathematically,

Density = Mass of an atom's nucleus ÷volume marked on the graduated cylinder

Atoms contains nucleus in its center and electron that revolve around the atom in fixed orbit.  The nucleus occupies very little of the volume but contains most of its mass.

Therefore,  the nucleus occupies very little of the volume but contains most of its mass. The correct option is option D.

To know more about density, here:

https://brainly.com/question/16894337

#SPJ2

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:

50 g

Explanation:

Please brainiest

Answer:

fe

Explanation:

forms one binary compounds with chlorine

Answer:

I think 5

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:

Glucose

Explanation:

Glucose is broken down into water and carbon dioxide.

hope this helps! :)

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:

0.967mole

Explanation:

Given parameters:

Volume of NH₄Cl  = 21.67L

Unknown:

Number of moles  = ?

Solution:

We assume that the volume was taken at standard temperature and pressure,

 Then;

  Number of moles  = [tex]\frac{volume }{22.4L}[/tex]  

 Number of moles  = [tex]\frac{21.67}{22.4}[/tex]   = 0.967mole

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

i tried i hope this helps hun  word “rain forest” implies that these are the some of the world’s wettest ecosystems. Rain forests generally receive very high rainfall each year, although the exact amount varies among different years and different rain forests.  For example, South America’s tropical rain forests receive between 200 and 300 centimetres (80 and 120 inches, or 6.5 to 10 feet!) of rain in a typical year. Despite relatively consistent rain in these ecosystems, there are distinct dry seasons in some rain forests. Wet and dry seasons of tropical rain forests vary in their timing, duration and severity around the globe. Tropical rain forests also have high humidity; about 88% during the wet season and approximately 77% in the dry season.

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: 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)