During chemical reactions the bonds between atoms break and new bonds form.

Energy must be absorbed to break a bond, so breaking bonds is endothermic.

Making new bonds is exothermic because energy is released.

a) When green copper carbonate decomposes, the equation is:












CuCO3 CuO CO2

copper carbonate copper oxide carbon dioxide


Is the reaction exothermic or endothermic? Use ideas about bonds to explain why.

Answer:

Normal boiling point is the temperature at which a liquid boils at 1 atmosphere of pressure.

Explanation:

Answer:

3. ethyne

Explanation:

Highest ratio of hydrogen to carbon? I'm not sure I found it on the internet but the answer is right

Answer:

What is the atomic number of neon?

10

What is the atomic mass of neon? Give your answer to the nearest tenth.

20.2

The periodic table is a representation of the periodic elements based on atomic numbers. The atomic number of neon is 10, and the atomic mass is 20.2 amu.

Neon is categorized as a stable gas that belongs to the noble gas group. It has been represented as Ne and is a monoatomic gas with no odor or color. It has an atomic number of 10 and an electronic configuration as, [He] 2s²2p⁶.

The atomic mass of neon elements is 20.2 amu and is said to have full electrons per shell. They do not need to donate or accept any electron as they have a balanced orbital. They have the property of fluorescence and are used in electric signs and lamps.

Therefore, neon is placed in group 18 and has atomic number 10 and a mass of 20.2 amu.

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Answer:

See explanation below

Explanation:

You forgot to put the picture to do so. In this case, I manage to find one, and I hope is the one you are looking for. If not, then post it again and I'll gladly help you out again.

According to the picture with the answer, we have a cyclohexane with 4 methyl groups there. Two of them are facing towards the molecule with a darker bond. This means that the alkyl bromide, should have a bromine in one of the bonds, and in order to produce an E2 reaction, this bromine should be facing in the opposite direction of the methyl groups which are facing towards. This is because an E2 reaction occurs with the less steric hindrance in the molecule. If the bromine is in the same direction as the methyl group, it will cause a lot more of work to do a reaction, and therefore, an E2 reaction. I will promote instead a E1 or a sustitution product.

Therefore the alkyl bromide should be like the one in the picture 2.

Answer:

D

Explanation:

Answer:

Industrial activity increases the emission of greenhouse gases in the atmosphere, especially carbon dioxide (CO2), and it negatively affects climate by increasing global warming.

Two actions to face the global warming:

1- To substitute the use of fossil fuels by alternative clean energy sources such as, for example, hydroelectric, geothermal, solar and wind energy resources.  

2- The government's policies decided to develop electric cars and to stimulate healthy habits such as walking instead of the use of conventional fossil-fueled transport modes.

Answer:

2Cl- ⇒ Cl ↓2+ 2e

Explanation: sorry if this is not what you were looking for.

Answer: to find a cure for the common cold to produce insulin for diabetics

Explanation: It has helped many people

Answer:

A)

Explanation:

Increasing of oxidation number shows that the process is oxidation(or losing of electrons).

-1 to +2, oxidation number is increased. This is an oxidation process.

-  

Answer:

49 g/L is the concentration of the acid

Explanation:

Firstly, we proceed to write the equation of reaction.

2NaOH + H2SO4 ——-> Na2SO4 + 2H2O

We can see that 1 mole of the base reacted with two moles of the acid.

kindly note that dm^3 is same as liter

Firstly, we need to get the concentration of the reacted sulphuric acid in g/L

we use the simple titration equation below;

CaVa/CbVb = Na/Nb

From the question;

Ca = ?

Va = 25 cm^3

Cb = 20 g/L

we convert this to concentration in mol/L

Mathematically, that is concentration in g/L divided by molar mass in g/mole

molar mass of NaOH = 40 g/mol

so we have; 20g/L / 40 = 0.5 mol/L

Vb = 50 cm^3

Na = 1

Nb = 2

Where C represents concentrations, V volumes and N , number of moles

Now, substitute the values;

Ca * 25/0.5 * 50 = 1/2

25Ca/25 = 0.5

So Ca = 0.5 mol/L

Now to get the concentration of H2SO4 in g/L

What we do is to multiply the concentration in mol/L by molar mass in g/mol

That would be 0.5 * 98 = 49 g/L

The concentration of the acid in grams per litre is 49g/L

From the question,

We are to determine concentration of the sodium hydroxide solution.

First, we will write a balanced chemical equation for the reaction.

The balanced chemical equation for the reaction is

2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O

This means,

2 moles of NaOH is required to completely neutralize 1 mole of H₂SO₄

From the formula

[tex]\frac{C_{A}V_{A} }{C_{B}V_{B} }=\frac{n_{A} }{n_{B} }[/tex]

Where

[tex]C_{A}[/tex] is the concentration of acid

[tex]C_{B}[/tex] is the concentration of base

[tex]V_{A}[/tex] is the volume of acid

[tex]V_{B}[/tex] is the volume of base

[tex]n_{A}[/tex] is the mole ratio of acid

[tex]n_{B}[/tex] is the mole ratio of base

From the question

[tex]V_{A}= 25 \ cm^{3}[/tex]

[tex]C_{B} = 20 \ g/dm^{3}[/tex]

Convert this to mol/dm³

Molar mass of NaOH = 40 g/mol

Using the formula

[tex]Concentration\ in \ mol/dm^{3} =\frac{Concentration\ in \ g/dm^{3}}{Molar\ mass}[/tex]

∴ Concentration of the NaOH in mol/dm³ = [tex]\frac{20}{40}[/tex]

Concentration of the NaOH in mol/dm³ = 0.5 mol/dm³

∴ [tex]C_{B} = 0.5 \ mol/dm^{3}[/tex]

and

[tex]V_{B} = 50 \ cm^{3}[/tex]

From the balanced chemical equation

[tex]n_{A} = 1[/tex]

[tex]n_{B} = 2[/tex]

Putting the parameters into the formula, we get

[tex]\frac{C_{A} \times 25}{0.5 \times 50}= \frac{1}{2}[/tex]

Now, this becomes

[tex]2 \times 25 \times C_{A}=0.5 \times 50 \times 1[/tex]

Then, we get

[tex]50 C_{A} = 25[/tex]

∴ [tex]C_{A} = \frac{25}{50}[/tex]

[tex]C_{A} = 0.5 \ mol/dm^{3} = 0.5 \ mol/L[/tex]

Now, we will determine the concentration in g/L

From the formula,

Concentration in g/L = Concentration in mol/L × Molar mass

From the question,

Molar mass of sulfuric acid = 98

∴ Concentration of the acid in g/L = 0.5 × 98

Concentration of the acid in g/L = 49 g/L

Hence, the concentration of the acid in grams per litre is 49g/L

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Answer: true

Explanation: hope this helpes

Answer:

TRUE

Explanation:

power derived from the utilization of physical or chemical resources, especially to provide light and heat or to work machines.

Answer:

D. Thermal conduction is blocked by the flip-flops.

Explanation:

Convection is a process of heat transfer which involves fluids( liquid or gas). This however rules convection out of the answer.

Radiation involves heat transfer from the sun to bodies on earth.

Conduction involves heat transfer between two solid bodies. Hot beach sand and flip-flops are solid bodies which validates thermal(heat) conduction.

Answer: D. 4,6,4

Explanation:

The valence electron is the electron found in the outermost shell of an atom, and participates in bond formation.

For the following element, the valence electron can be noticed when we write the electronic configuration of each element.

Silicon =  1s2 2s2 2P6 3s2 3p2

Sulphur = 1s2 2s2 2P6 3s2 3p4

Germanium =  1s2 2s2 2P6 3s2 3p6 3d10 4s2 4p2

Answer:

The answer is 80!

Explanation:

A prism is a three dimensional solid object in which the two ends are identical. It is the combination of the flat faces, identical bases and equal cross sections. The volume of the prism is 819 cm³.

A prism is a polyhedron with two parallel congruent faces called the bases that are polygons. The volume of a three dimensional solid is the amount of space it occupies. The volume is measured in cubic units. The volume can be denoted in m³, cm³, ft³, etc.

The volume of a prism is the area of the base times the height. The equation used to calculate the volume is:

Volume = Base area × Height

Here the rectangle has 9cm length and 7cm width. Then the area is:

Area = 9 × 7 = 63 cm²

The height of prism = 13 cm

Then the volume is:

V = 63 × 13 = 819 cm³

Thus the volume of the prism is 819 cm³.

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Your question is incomplete most probably your full question was

What is volume of the rectangular prism with length 9cm, width 7cm and height  13 cm?

Answer:

1) 1.39 grams H2O2

2) 0.933 grams Fe

Explanation:

Step 1: Data given

Volume of oxygen = 0.460 L

STP = 1 atm and 273 K

Step 2: The balanced equation

2H2O2(aq) → 2H2O(l) + O2(g)

Step 3: Calculate the number of moles O2

p*V = n*R*T

⇒with p= the pressure = 1 atm

⇒with V = the volume = 0.460 L

⇒with n = the number of moles = TO BE DETERMINED

⇒with R = the gas constant = 0.08206 L*atm/mol*K

⇒with T = the temperature = 273 K

n = (p*V)/(R*T)

n = (1 * 0.460)/ (0.08206*273)

n = 0.0205 moles moles

Step 4: Calculate moles H2O2

For 2 moles H2O we'll have 2 moles H2O and 1 mol O2

For 0.0205 moles O2 we'll need 2*0.0205 = 0.041 moles H2O2

Step 5: Calculate mass H2O2

Mass H2O2 = moles H2O2 * molar mass H2O2

Mass H2O2 = 0.041 moles * 34.01 g/mol

Mass H2O2 = 1.39 grams

Step 1: Data given

Volume of hydrogen = 0.500 L

STP = 1 atm and 273 K

Step 2: The balanced equation

3Fe(s) + 4H2O(l) → Fe3O4(s) + 4H2(g)

Step 3: Calculate the moles of H2

p**V = n*R*T

⇒with p= the pressure = 1 atm

⇒with V = the volume = 0.500 L

⇒with n = the number of moles = TO BE DETERMINED

⇒with R = the gas constant = 0.08206 L*atm/mol*K

⇒with T = the temperature = 273 K

n = (p*V) / '*T)

n = (1 * 0.500) / (0.08206 * 273)

n = 0.0223 moles

Step 4: Calculate moles Fe

For 3 moles Fe we need 4 moles H2O to produce 1 mol Fe3O4 and 4 moles H2

For 0.0223 moles H2 we'll need 0.0223 *3/4 = 0.0167 moles Fe

Step 5: Calculate mass of Fe

Mass Fe = moles Fe * atomic mass Fe

Mass Fe = 0.0167 moles * 55.845 g/mol

Mass Fe = 0.933 grams Fe

1. The mass of the hydrogen peroxide should be 1.39 grams H2O2.

2) The mass of the iron should be 0.933 grams Fe.

Since

Volume of oxygen = 0.460 L

STP = 1 atm and 273 K

Now The balanced equation

2H2O2(aq) → 2H2O(l) + O2(g)

Now the number of moles O2

p*V = n*R*T

Here p= the pressure = 1 atm

V = the volume = 0.460 L

n = the number of moles = ?

R = the gas constant = 0.08206 L*atm/mol*K

T = the temperature = 273 K

Now

n = (p*V)/(R*T)

n = (1 * 0.460)/ (0.08206*273)

n = 0.0205 moles moles

Now  moles H2O2 should be

For 2 moles H2O we'll have 2 moles H2O and 1 mol O2

So,

For 0.0205 moles O2 we'll need 2*0.0205 = 0.041 moles H2O2

Now mass H2O2

Mass H2O2 = moles H2O2 * molar mass H2O2

Mass H2O2 = 0.041 moles * 34.01 g/mol

Mass H2O2 = 1.39 grams

2. The mass of the iron should be

Since

Volume of hydrogen = 0.500 L

STP = 1 atm and 273 K

Now

The balanced equation

3Fe(s) + 4H2O(l) → Fe3O4(s) + 4H2(g)

Now the moles of H2

p**V = n*R*T

Here

p= the pressure = 1 atm

V = the volume = 0.500 L

n = the number of moles = ?

R = the gas constant = 0.08206 L*atm/mol*K

T = the temperature = 273 K

So,

n = (p*V) / '*T)

n = (1 * 0.500) / (0.08206 * 273)

n = 0.0223 moles

Now Calculate moles Fe

For 3 moles Fe we need 4 moles H2O to produce 1 mol Fe3O4 and 4 moles H2

So,

For 0.0223 moles H2 we'll need 0.0223 *3/4 = 0.0167 moles Fe

Now the mass of Fe

Mass Fe = moles Fe * atomic mass Fe

Mass Fe = 0.0167 moles * 55.845 g/mol

Mass Fe = 0.933 grams Fe

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Answer:

kinetic energy. (General Physics) the energy of motion of a body, equal to the work it would do if it were brought to rest. The translational kinetic energy depends on motion through space, and for a rigid body of constant mass is equal to the product of half the mass times the square of the speed.

Answer:it is the simplest one

the energy possessed by a body due to its motion is called kinetic energy

K.E.=[tex]\frac{1}{2}[/tex]mv²

Answer:

A group of cells working together is defined as a tissue and several tissues working together comprise an organ.

Explanation:

Answer: Using a dry tea towel to grab a hot pan puts the heat into the towel fibers, which are poor conductors of heat, and which serve to separate your hand from the hot pan by a set of air gaps.

A dry towel is a better insulator than a wet towel. Because the water in the wet towel fills the empty spaces between the fibers of the towel and helps to conduct heat. Therefore, it is much safer to pick up hot dishes with a dry cloth than a wet one.

Conduction can be described as the process by which heat is transferred from the hotter to the colder end of an object. The capability of the object to conduct heat is its thermal conductivity.

Heat flows along a temperature gradient. Heat is conducted from the hot plate of a stove to the bottom of a saucepan in contact with it, which is an example of thermal conduction.

In solids, conduction is the combination of vibrations and collisions of molecules, propagation and collisions, and diffusion of free electrons. In gases and liquids, conduction is due to the diffusion and collisions of molecules while their random motion. Therefore, thermal conduction will be faster in a wet towel than in a dry towel.

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Answer:

Since most of the data scientist collect is quantitative, data tables and charts are usually used to organize the information • Graphs are created from data tables • hope that helps love!

Answer:

Acid is a compound which dissolves in water to produce hydrogen ions (H+) and described as proton donors.

Answer:

they should have a number that can completely transfer and fill the other atom

Explanation:

example:

sodium(2.8.1)and Chlorine(2.8.7)the sodium will give chlorine the 1 valence electrobo so they both become stable(2.8)±and(2.8.8)–

magnesium(2.8.2)and oxygen(2.6)same way as above to abtain mg(2.8)±²and oxygen(2.8)–²

Answer:

yh you are correct. the pattern is correct! :)

Answer:

Yep! :)

Explanation:

Answer:

Sulfur?

Explanation:

Sulfur has 6 valence electrons and does not have luster.

Answer:

Solute

Explanation:

Answer:

C. The electron clouds are negatively charged and repel each other as far apart as possible

Explanation:

This is the basis of VSEPR theory.

The angles between the electron clouds determine the shapes of the molecules.

B. and D. are wrong. All electron pairs are negatively charged.

The electrons affect the structure of a molecule because the bonding pairs are positively charged and lone pairs are negatively charged and they push each other into certain shapes.

Every atom or molecule consist some kind of geometry or shapes like linier, tetrahedral, square planner, octahedral etc. with some bond length and angles present with them.

The bond pairs in a geometry is made up with positive charge and lone pairs present on the atom in the form of negative charge as they both are opposite in nature and repel or push each other in opposite direction.

Due to this phenomena the structure of the atom gets effected and geometry will change on the basis of lone pair and bond pair repulsion.

Therefore, electrons affect the structure of a molecule because the bonding pairs are positively charged and lone pairs are negatively charged and they push each other into certain shapes.

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Answer:

[tex]\large \boxed{\text{299.4 g}}[/tex]

Explanation:

We will need a chemical equation with masses and molar masses, so, let's gather all the information in one place.

Mᵣ:        44.10                          44.01

              C₃H₈   +   5O₂   ⟶   3CO₂   +   4H₂O

m/g:  100.00

To solve a stoichiometry problem, you must

1. Moles of C₃H₈

[tex]\text{Moles of C$_{3}$H}_{8} = \text{100.00 g C$_{3}$H}_{8} \times \dfrac{\text{1 mol C$_{3}$H}_{8}}{\text{44.10 g C$_{3}$H}_{8}} = \text{2.268 mol C$_{3}$H}_{8}[/tex]

2. Moles of CO₂

The molar ratio is 3 mol CO₂:1 mol C₃H₈

[tex]\text{Moles of CO}_{2} = \text{2.268 mol C$_{3}$H}_{8} \times \dfrac{\text{3 mol CO}_{2}}{\text{1 mol C$_{3}$H}_{8}} = \text{6.803 mol CO}_{2}[/tex]

3. Mass of CO₂

[tex]\text{Mass of CO}_{2} = \text{6.803 mol CO}_{2} \times \dfrac{\text{44.01 g CO}_{2}}{\text{1 mol CO}_{2}} = \textbf{299.4 g CO}_{2}\\\text{The mass of CO$_{2}$ required is $\large \boxed{\textbf{299.4 g}}$}[/tex]

Answer:

Number of moles of propane:

=Mass in grams ÷ Relative molecular Mass

= 100/((12*3) + (1*8))

= 100 ÷ 44

= 2.2727

Mole ratio propane:carbon (IV) oxide = 1:3(from the equation)

Number of moles of CO2 = 3*2.2727 = 6.8181

Mass in grams = Relative molecular Mass * Number of moles

= 44 * 6.8181

= 299.9964 grams

Explanation:

Answer:

the particles with a negative charge are protons