Calculate the grams of calcium present in 70 grams of calcium chloride.

Answer:

A) anaerobic respiration

B) photosynthesis

C) breathing

Answer:

(i) rusting is caused by the reaction of oxygen and water on the surface of metals(iron).

(ii) rusting of iron makes it weak and dangerous for buildings since their foundation is made of iron, rusting renders cars useless, rusting can cause accidents.

(iii) by galvanizing iron

and by coating it.

Explanation:

hope it helps .

Answer:

waves that move through matter only are called mechanical waves.

waves that move through space only are called electromagnetic waves.

Waves that move through matter only are called

(mechanical) waves.

Waves that move through space are called

(electromagnetic) waves.

Could I get a brainliest please?

Answer:  A. 28

If we aren't talking about an isotope, then the number of neutrons and the number of protons in the nucleus are the same. Each proton weighs one atomic unit, and the same can be said about a neutron as well. So half of the weight is from the protons and half is from the neutrons. The electrons are extremely small relative to the protons that their weight is negligible.

Answer:

They assumed they both had water.

Explanation:

Because they only could look at it through telescopes that were not advanced

Answer:

D.

Explanation:

In a Galvanic cell:

1) Spontaneous reactions take place

2) Chemical Energy is converted to some useful electrical energy

Answer:

Explanation:

En este caso para formular los compuestos, debes identificar el grupo funcional principal de la molecula. Una vez que eso está hecho, puedes intentar formularlo.

Empezaremos primero identificando el grupo funcional principal de la molécula, para luego formularlo correctamente.

Dietil eter: la terminación eter al final significa que pertenece al grupo de los éteres, el cual tiene como formula general R - O - R.

Etanol: debido a que termina en ol, este grupo pertenece a los alcoholes. Para formularlo solo se dibuja la molecula del etano, junto a un enlace con el grupo OH, como su formula general R - OH.

Propanotriol: igualmente termina en ol, por lo tanto es un alcohol, sin embargo, en este caso, tambien tiene la terminación prefija tri, asi que significa que hay 3 grupos OH en la molecula.

Acido propanodioico: esta es sencilla, porque empieza como acido, y solo hay un grupo funcional que empieza así y son los acidos carboxilicos, es decir, el grupo COOH (R - COOH) que es el carboxilo. Tiene el prefijo di, antes del oico, por lo que son dos carboxilos presentes en la molecula.

Pentanal: el sufijo al, significa que pertenece al grupo de los aldehidos, en este caso, posee el grupo carbonilo H - C = O.

Pentano - 2,4 - diona: la terminación ona significa que pertenece al grupo de las cetonas, (R - CO - R), parecido a los aldehidos, con la diferencia de que tiene grupos alquilos en lugar de un hidrogeno.

Metanoato de metilo: la terminación ato de ilo, pertenece a los esteres, (R - COOR) derivado de los acidos carboxilicos.

De aqui en adelante solo mencionaré los grupos funcionales pues ya se explicó el por que, por sus terminaciones:

Ciclohexano - 1.3 - diol: este pertenece a los alcoholes.

Acido heptanoico: acido carboxilico

Ciclobutil metil eter: eteres

Acetato de etilo: ester

2-metilbenzaldehído: aldehído unido a un grupo aromatico como el benceno.

Ciclohexanona: un ciclo (cadena cerrada) unido a un grupo carbonilo.

Butanona: cetona.

Observa la foto adjunta para que veas la formulación de cada una:

Answer:

1.68 atm.

Explanation:

Given:

P1 = 4.23atm

V1 = 1870 mL

T1 = 293K

P2 = ?

V2 = 6.01 L = 6010 mL

T2 = 373 K

Assuming number of moles and R is constant:

[tex]\frac{P1V1}{T1} = \frac{P2V2}{T2}[/tex]

⇒ P2 = [tex]\frac{P1V1T2}{T1V2}[/tex] = [tex]\frac{2,950,467.3}{1,760,930}[/tex]

= 1.68 atm.

Answer: The mass of [tex]4.65\times 10^{22}[/tex] molecules of phosphorus pentoxide is 20.5 g

Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to the molecular mass and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.

To calculate the moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given molecules}}{\text {avogadro's number}}=\frac{4.65\times 10^{22}}{6.023\times 10^{23}}=0.0772moles[/tex]

1 mole of [tex]P_2O_5[/tex] weigh =  283.9 g

Thus 0.0772 moles  of [tex]P_2O_5[/tex] weigh = [tex]\frac{283.9}{1}\times 0.0722=20.5g[/tex]

Thus the mass of [tex]4.65\times 10^{22}[/tex] molecules of phosphorus pentoxide is 20.5 g

Answer:

Il of the above are part of the Kinetic Molecular Theory

Explanation:

Answer: Which of the following are part of kinetic-molecular theory?

Choices:

1. The particles in a solid do not move.

2. The particles in a liquid are moving past one another constantly.

3. The particles in gas move freely in all directions.

4. The particles in a solid vibrate in a fixed position.

5. The particles in a solid are far apart.

6. The particles in a gas have few attractions between them.

7. The particles in all states of matter are always moving.

Explanation: Which of the following are part of kinetic-molecular theory...

Answers:

2. The particles in a liquid are moving past one another constantly.

3. The particles in gas move freely in all directions.

4. The particles in a solid vibrate in a fixed position.

6. The particles in a gas have few attractions between them.

7. The particles in all states of matter are always moving.

Answer:

1.507 moles of CO₂ are released daily by a hummingbird's respiration

Explanation:

The reaction of production of carbon dioxide and water from sugar is:

C₁₂H₂₂O₁₁ + 12O₂ → 12CO₂ + 11H₂O

Where 1 mole of sugar produce 12 moles of CO₂

Molar mass of sugar (To convert the mass to moles) is:

12C = 12ₓ12.01g/mol = 144.12g/mol

22H = 22ₓ1.01g/mol = 22.22g/mol

11O = 11ₓ16g/mol = 176g/mol

144.12 + 22.22 + 176 = 342.34g/mol

Thus, moles of 43.0g of sugar are:

43.0g ₓ (1mol / 342.34g) = 0.1256 moles of sugar.

As 1 mole of sugar produce 12 moles of CO₂:

0.1256 moles of sugar ₓ (12 moles CO₂ / 1 mol sugar) =

Answer:

Sodium sulfide is the chemical compound with the formula Na2S, or more commonly its hydrate Na2S·9H2O. Both the anhydrous and the hydrated salts are colorless solids. They are water-soluble, giving strongly alkaline solutions. When exposed to moist air, Na2S and its hydrates emit hydrogen sulfide, which smells like rotten eggs. Some commercial samples are specified as Na2S·xH2O, where a weight percentage of Na2S is specified. Commonly available grades have around 60% Na2S by weight, which means that x is around 3. Such technical grades of sodium sulfide have a yellow appearance owing to the presence of polysulfides. These grades of sodium sulfide are marketed as 'sodium sulfide flakes'.

Contents

1 Structure

2 Production

3 Reactions with inorganic reagents

4 Uses

4.1 Reagent in organic chemistry

5 Safety

6 References

Structure

Na2S adopts the antifluorite structure,[2][3] which means that the Na+ centers occupy sites of the fluoride in the CaF2 framework, and the larger S2− occupy the sites for Ca2+.

Production

Industrially Na2S is produced by carbothermic reduction of sodium sulfate often using coal:[4]

Na2SO4 + 2 C → Na2S + 2 CO2

In the laboratory, the salt can be prepared by reduction of sulfur with sodium in anhydrous ammonia, or by sodium in dry THF with a catalytic amount of naphthalene (forming sodium naphthalenide):[5]

2 Na + S → Na2S

Reactions with inorganic reagents

The sulfide ion in sulfide salts such as sodium sulfide can incorporate a proton into the salt by protonation:

S2−

+  H+ → SH−

Because of this capture of the proton ( H+), sodium sulfide has basic character. Sodium sulfide is strongly basic, able to absorb two protons. Its conjugate acid is sodium hydrosulfide (SH−

). An aqueous solution contains a significant portion of sulfide ions that are singly protonated.

S2−

+ H

2O {\displaystyle {\ce {<=>>}}}{\displaystyle {\ce {<=>>}}} SH−

+  OH−

(1)

SH−

+ H

2O {\displaystyle {\ce {<<=>}}}{\displaystyle {\ce {<<=>}}} H

2S +  OH−

(2)

Sodium sulfide is unstable in the presence of water due to the gradual loss of hydrogen sulfide into the atmosphere.

When heated with oxygen and carbon dioxide, sodium sulfide can oxidize to sodium carbonate and sulfur dioxide:

2 Na2S + 3 O2 + 2 CO

2 → 2 Na2CO3 + 2 SO2

Oxidation with hydrogen peroxide gives sodium sulfate:[6]

Na2S + 4 H2O2 → 4 H

2O + Na2SO4

Upon treatment with sulfur, polysulfides are formed:

2 Na2S + S8 → 2 Na2S5

Uses

Sodium sulfide is primarily used in the kraft process in the pulp and paper industry.

It is used in water treatment as an oxygen scavenger agent and also as a metals precipitant; in chemical photography for toning black and white photographs; in the textile industry as a bleaching agent, for desulfurising and as a dechlorinating agent; and in the leather trade for the sulfitisation of tanning extracts. It is used in chemical manufacturing as a sulfonation and sulfomethylation agent. It is used in the production of rubber chemicals, sulfur dyes and other chemical compounds. It is used in other applications including ore flotation, oil recovery, making dyes, and detergent. It is also used during leather processing, as an unhairing agent in the liming operation.

Reagent in organic chemistry

Alkylation of sodium sulfide give thioethers:

Na2S + 2 RX → R2S + 2 NaX

Even aryl halides participate in this reaction.[7] By a broadly similar process sodium sulfide can react with alkenes in the thiol-ene reaction to give thioethers. Sodium sulfide can be used as nucleophile in Sandmeyer type reactions.[8] Sodium sulfide reduces1,3-dinitrobenzene derivatives to the 3-nitroanilines.[9] Aqueous solution of sodium sulfide can be refluxed with nitro carrying azo dyes dissolved in dioxane and ethanol to selectively reduce the nitro groups to amine; while other reducible groups, e.g. azo group, remain intact.[10] Sulfide has also been employed in photocatalytic applications.[11]

Explanation:there you go

When sodium combines with sulphur, it formed sodium sulphide. When it interacts with sulfur, polysulfides are produced. Additionally, heat causes sodium sulfide to oxidize fast. Sulfur dioxide and sodium carbonate are the end products.

Chemical element sulfur has the letter S and atomic number 16. It is multivalent, nonmetallic, and plentiful. Sulfur atoms normally combine to create cyclic octatomic molecules, which have the chemical formula S₈.

At room temperature, elemental sulfur is a crystalline solid that is brilliant yellow. It is employed in the production of fertilizer, water treatment, mineral extraction, oil refining, and automobile batteries.

Other uses for compounds based on sulfur include vulcanizing rubber, bleaching paper, and producing goods like cement, detergents, and insecticides.

Thus, When sodium combines with sulphur, it formed sodium sulphide.

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Answer:

The displacement reactions are regarded as redox reactions because they involve the formal transfer of electrons from one chemical specie to the other

2) The series of reactivity of the metals in the order of increasing reactivity are;

           ↓

           ↓

Explanation:

1) Redox (oxidation-reduction) reaction is a chemical reaction involving the loss and gain of electrons from one chemical species to another, where the chemical species that undergoes oxidation, loses electrons and is termed the reducing agent, while the other chemical species that undergoes reduction, gains electrons, and is termed the oxidizing agent

2) The redox reaction can being based on the affinity for electrons depends on the positions of the reactants in the electrochemical series as well as the chemical reactivity of the metals with zinc being a stronger reducing agent and more chemically reactive than copper and magnesium being a stronger reducing agent and more chemically reactive than zinc

Least  reactive (Cu)  <     (Zn)        < Mg Most reactive

Copper                     <      Zinc       < Magnesium.

Answer:

Food in the stomach that is high in protein will dilute absorption of alcohol in your stomach :) therefore always drink with food in your stomach, just drinking alchol without food will have serious consequences on helath.

Explanation:

Answer:

trimolecular

Explanation:

Answer:

Coke, coal gas, gas carbon, ammonia liquor, and coal oil 

Answer:

Iron is oxidized to form rust.

Explanation:

Consider the reaction; 4Fe + 302------>2Fe2O3, we can see that iron is being oxidized to iron III oxide. Rust is the common name of iron III oxide.

Rusting is an electrochemical process, iron rusts when it comes into contact with air and water because electrochemical cells are set up at the surface of contact.

Iron usually functions as the anode in the electrochemical process. This process leads to the formation of iron III oxide. Rust is soft and breaks off easily thereby exposing the metal below the surface to further rusting.

Answer:

Iron is oxidized to form rust.

Explanation:

edge

Answer:

0.086J/g°C

Explanation:

The following data were obtained from the question:

Mass (M) = 30g

Initial temperature (T1) = 10°C

Final temperature (T2) = 45°C

Change in temperature (ΔT) = T2 – T1 = 45°C – 10°C = 35°C

Heat (Q) released = 90J

Specific heat capacity (C) of wood =..?

We can obtain the specific heat capacity of the wood as follow:

Q = MCΔT

90 = 30 x C x 35

Divide both side by 30 x 35

C = 90/(30 x 35)

C = 0.086J/g°C.

Therefore, the specific heat capacity of the wood is 0.086J/g°C.

Answer:

Chemical Change

Explanation:

Mixing these elements together creates a chemical change

Making of a salad dressing is a physical change  as there is no change in the chemical composition.

Physical changes are defined as changes which affect only the form of a substance but not it's chemical composition. They are used to separate mixtures in to chemical components but cannot be used to separate compounds to simpler compounds.

Physical changes are always reversible using physical means and involve a change in the physical properties.Examples of physical changes include melting,boiling , change in texture, size,color,volume and density.Magnetism, crystallization, formation of alloys are all reversible and hence physical changes.

They involve only rearrangement of atoms and are often characterized to be changes which are reversible.

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Answer:

The ionisation energy increases.

Explanation:

This is because the force of attraction between the electrons and the positive nucleus will increase

Answer:

Explanation:F

What is pollen in the reproduction cycle of flowering plants?

A pollen grain is a microspore containing the male gametophyte, usually reduced to two undivided cells, each with one haploid (n) nucleus. These cells are surrounded by a very resistant wall, the exine, which generally has apertures, zones with less resistance which will allow the germination of the pollen tube.

Explanation of the reproduction cycle (cf diagram above)

A given species produces flowers bearing stamens. According to species, these flowers can be unisexual (stamens only) or bisexual (stamens and carpels).

The stamen anthers include 4 pollen sacs containing sporogenous cells (diploid=2n). These sporogenous cells undergo meiosis, each producing 4 microspores (haploid=n). Two nuclei are then formed by mitosis : the vegetative nucleus and the generative nucleus. The latter divides to form 2 sperms. Simultaneously the wall of the microspores becomes thicker and takes the characteristic shape of the species : it is a pollen grain (see: What are the morphological characteristics of pollen and spore grains?). In the majority of species, the 4 grains (resulting from the 4 microspores) split up into single grains; in some cases, they remain together (tetrad = group of 4 grains). When mature, pollen grains are released by the opening of the anthers.

A pollen grain is aimed at reaching another flower of the same species, bearing carpels. The ovaries contain ovules, in which meiosis occurs, then mitoses. It results in an embryo sac with 8 nuclei, among which an egg cell and 2 central cells. When a pollen grain arrives on another flower (see : How are the spores and pollen grains transported?), it is received by the stigmas.

The pollen grain germinates through an opening of the wall: the vegetative nucleus develops into a pollen tube which is guided by the style to the ovary, then enters the micropyle of an ovule. The pollen tube releases 2 sperm nuclei into the ovule: one of the sperms fuses with the egg cell into a zygote (2n), while the other sperm fuses with central nuclei and gives rise to albumen (= food source). There are generally several ovules in an ovary : each one can be fertilized by a distinct pollen grain.

Each fertilized ovule and its albumen form a seed that will develop into a new individual of this species. hope it works

Answer:

pollen

Explanation:

you insolent vacuum

Answer:

c is the speed of light

Explanation:

E: energy

m: mass

c2: speed of light squared

Answer:

i)a. P & R

b. Q& S

ii) R

iii) Atomic no & Atomic radius

2)a. C4H10

b. CH3Cl

Answer: Because alchemy was based on mystical belief instead of the scientific method.Soo.. Chemistry uses experiments to test ideas whereas alchemy used superstitious practices.

Explanation:

Answer:

that was because Alchemy was based on experimentation and had little basis in Science, while Chemistry utilizes both experimentation and scientific practices.

Explanation:

Answer:

A

Explanation:

Answer:

Noble gases are a unique set of elements in the periodic table because they don't naturally bond with other elements.

Explanation:

HAVE A GOOD DAY!

Answer:

The answer is Noble Gases!!

Explanation:

Hope i helped yall! Have a super fantastic day!! Play Among Us! (Of course when your done with school) lol, jk, but u can!! Byes yall!

Answer:

mushroom

mold

spore cases

hyphae

fungus