pls Help ASAP - Calcium reacts with oxygen to produce calcium oxide. What mass of calcium oxide is produced when 10g of calcium burns?
Please show your working out.

Answer:

No

Explanation:

In the hot pack, as the water reacts with the magnesium sulfate, the pack becomes bigger is not an indication that new atoms have been created or produced.

As with all chemical reactions, they all obey the law of conservation of matter which states that "in chemical reactions, matter is neither created nor destroyed but atoms simply recombine".

The reason why the hotpack becomes bigger is because the atoms gain more volume.

Answer: 7.80×[tex]10^{22}[/tex][tex]\frac{1}{6.02*10^{23} }[/tex] =.13

Explanation:

The number of moles that are present in 7.80 × 10²² molecules of HCl is 0.13 moles

The number of moles of a substance is defined as the mass of the substance divided by the molar mass of such a substance. Also, one mole of a substance is synonymous and equal to 6.023 × 10²³ Avogadro's number.

Therefore, the number of moles that are present in 7.80 × 10²² molecules of HCl can be computed as:

[tex]\mathbf{=\Big(7.80 \times 10^{22} \times \dfrac{1}{6.02\times 10^{23} }\Big)\ moles}[/tex]

= 0.12956 moles

≅ 0.13 moles of HCl

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Answer:

3.66 g de 2-feniletanol (C5H5-CH2-CH2-OH)

1.8 * 10 ^ 22 moléculas

Explanation:

Sabemos que podemos obtener la masa de una sustancia a partir del número de moles presentes de la siguiente manera;

número de moles = masa / masa molar

masa molar de 2-feniletanol (C5H5-CH2-CH2-OH) = 122,16 g / mol

masa = 0.03 moles * 122.16 g / mol = 3.66 g de 2-feniletanol (C5H5-CH2-CH2-OH)

Si 1 mol = 6.02 * 10 ^ 23 moléculas

0.03 moles = 0.03 moles * 6.02 * 10 ^ 23 moléculas = 1.8 * 10 ^ 22 moléculas

Answer:

imma go with the answer B

The product in the reaction  [tex]\rm Zn + 2HCl \rightarrow[/tex] is [tex]\rm ZnCl_2 + H_2[/tex]. The correct answer is option D.

A reaction is a process that involves the transformation of one or more substances into one or more different substances.

The reaction between zinc (Zn) and hydrochloric acid (HCl) is a classic example of a single displacement reaction. In this reaction, zinc reacts with hydrochloric acid to produce zinc chloride ([tex]\rm ZnCl_2[/tex]) and hydrogen gas ([tex]\rm H_2[/tex]).

The balanced chemical equation for this reaction is:

[tex]\rm Zn(s) + 2HCl(aq) \rightarrow ZnCl_2(aq) + H_2(g)[/tex]

Therefore, the product of the reaction between zinc and hydrochloric acid is zinc chloride ([tex]\rm ZnCl_2[/tex]) and hydrogen gas ([tex]\rm H_2[/tex]). Option D is the correct answer.

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Answer:

Cilindros graduados

Explanation:

Son una herramienta de medición primaria para el volumen de un líquido, y tiene varias marcas hacia arriba y hacia abajo a lo largo del contenedor con incrementos específicos. Los cilindros graduados vienen en muchos tamaños; entre más pequeños sean de diámetro, más específicas serán las mediciones de volumen. Al leer el volumen de un cilindro graduado, notarán que el líquido parece tener una muesca; el líquido alrededor de los bordes será más alto que el líquido en el centro, inclinándose hacia abajo como los lados de un trampolín cuando alguien está parado en el medio. Esto se llama el menisco. Alineen el punto más bajo del menisco con la marca más cercana, manteniendo el nivel del cilindro para leer correctamente el volumen.

Answer:

12 moles H2O

Explanation:

Your tools of choice for stoichiometry problems will always be the mole ratios that exist between the chemical species that take part in the reaction.

As you know, the stoichiometric coefficients attributed to each compound in the balanced chemical equation can be thought of as moles of reactants needed or moles of products formed in the reaction.

In your case, the balanced chemical equation for this synthesis reaction looks like this

2H2(g]+O 2(g]→2H2O(l]]

Notice that the reaction requires

2

moles of hydrogen gas and

1

mole of oxygen gas to produce

2

moles of water.

This tells you that the reaction produces twice as many moles of water as you have moles of oxygen gas that take part in the reaction.

You know that your reaction uses

6.0

moles of oxygen. Assuming that hydrogen gas is not a limiting reagent, you can say that the reaction will produce

6.0

moles O

2⋅2

moles H

2O1

moles O

2=

12 moles H2O

There are four equivalent best resonance structures of (PO₄)₃ according to the concept of resonance.

The phenomenon of resonance which is also called mesomerism is the ability of the molecules or ions to explain the bonding in them by the combination of several canonical structures.

It is an extension of Lewis structures to describe bonding in chemical species.The resonance structures also include the fractional charges present on the atom .They are capable of of depicting delocalized electrons which are unable to be depicted by single Lewis structure.

Molecules with extended pi system are well defined by resonance hybrids.It is a way of giving description of bonding in certain molecules.When there is passage of electrons through pi structures which are opposing ,resonance occurs.

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Answer:

its the sun

Explanation:

Answer:

Alkenes contain a double bond that is composed of one sigma and one pi bond between two carbon atoms. The sigma bond has similar properties to those found in alkanes , while the pi bond is more reactive. The carbon atoms in the double bond are sp² hybridized , forming a planar structure.

Explanation:

Believe it!!!

Answer:

Same.

Explanation:

The temperature of each 400mL bucket is about the same as the temperature of the original bucket of paint.

This is because the temperature is an intrinsic property.This means that temperature is independent of the quantity of matter. Therefore, the temperature of paint inside the bucket is not dependent on the amount of paint present.

Answer:

Avogadro proposed that equal volumes of gases under the same conditions contain the same number of molecules, and hypothesis that proved useful in determining atomic and molecular weights and which led to the concept of mole.

Explanation:

"The mole is important because it allows chemists to work with the subatomic world with macro world units and amounts. Atoms, molecules and formula units are very small and very difficult to work with usually. However, the mole allows a chemist to work with amounts large enough to use."

- Source socratic.org

Hope this helped!

Answer:

C. Niche

Explanation:

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

Answer:

metallic bonds.

Explanation:

Generally, compounds that are ductile and excellent conductor of electricity have metallic bonds between them.

These compounds are usually metals.

Answer:

5.14mole

Explanation:

Given parameters:

Mass of sodium bicarbonate  = 431.56g

Unknown:

Number of moles  = ?

Solution:

To find the number of moles, we use the expression below:

  Number of moles  = [tex]\frac{mass}{molar mass}[/tex]  

 Molar mass = 84.01g/mol

 Number of moles  = [tex]\frac{431.56}{84.01}[/tex]   = 5.14mole

Answer:

2.35 x 10²³atoms

Explanation:

Given parameters:

Number of moles of Be  = 0.39moles

Unknown:

Number of atoms  = ?

Solution:

To solve this problem:

                1 mole of a substance contains 6.02 x 10²³ atoms

               0.39 mole of Be will contain 0.39 x 6.02 x 10²³ = 2.35 x 10²³atoms

Answer:

Lime(Calcium Oxide) is a white solid with strongly basic properties.Lime reacts readily with water to produce slaked lime,which is the chemical compound calcium hydroxide.....

When carbon dioxide gas is passed through or over limewater,it turns milky due to the formation of calcium carbonate.

Answer:

The statement that best describes the use of catalytic converters in automobiles is;

They oxidize hydrocarbons to form less toxic gases

Explanation:

Catalytic converters

A working engine produces some air pollutants which are made due to fuel not completely burnt in the engine, including unburnt gasoline (a hydrocarbon), nitrogen oxides, and carbon monoxide

Carbon monoxide is poisonous to breathe in if present in the air around us, and nitrogen oxides causes acid rain and smog, while hydrocarbon from the gasoline causes smog

The catalyst in the catalytic converters aids in the conversion of the harmful gases produced by the car engine into harmless gases such as the types of gases already existing in the atmosphere and therefore, can be released into the air

The catalysts in the catalytic converter work by either oxidizing some of the harmful gases such as the unburnt hydrocarbons, or by reducing the other harmful gases such as the nitrogen oxides.

Therefore, the statement that best describes the use of catalytic converters in automobiles is that they oxidize hydrocarbons to form less toxic gases

Answer:

b

Explanation:

got it right on test

Answer:

fgedhwkmgfvhcdnxj

Explanation:

gtryijdohuygfvbhgfy

Answer:

4.32 [tex]\frac{1}{18.01}[/tex] ×[tex]\frac{22.4}{1}[/tex] = 5.37

Explanation:

22.4 is how many liters per mole. 18.01 is the mass of H2O.

Answer: A and C

Explanation: because wavelength is the distance over which the wave's shape repeats.

Wave A and wave C have the same wavelength as they have the same distance between the two adjacent crests or troughs. Therefore, option (2) is correct.

The wavelength of the wave can be defined as the distance between consecutive adjacent points of the same phase on the wave. The separation between the two adjacent crests or troughs on a wave is known as wavelength.

The S.I. unit of the wavelength can be represented in meters. Wavelength is a characteristic of both standing waves and traveling waves, as well as other spatial wave patterns.

The frequency of the wave can be demonstrated as the number of oscillations of a wave in 1 second. The international S.I. units of the frequency can be represented as per second or Hertz.

The relationship between wavelength, speed of light (c), and frequency (ν) is: c = νλ

Therefore, wave A and wave B have the same wavelength in the given diagram.

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Answer:

gas

Explanation:

its either gas or plasma but gas should be it bc liquid and solid are cold

Answer:

c = 0.898 J/g.°C

Explanation:

1) Given data:

Mass of water = 23.0 g

Initial temperature = 25.4°C

Final temperature = 42.8° C

Heat absorbed = ?

Solution:

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

Specific heat capacity of water is 4.18 J/g°C

ΔT = 42.8°C - 25.4°C

ΔT = 17.4°C

Q = 23.0 g ×  × 4.18 J/g°C × 17.4°C

Q = 1672.84 j

2) Given data:

Mass of metal = 120.7 g

Initial temperature = 90.5°C

Final temperature = 25.7 ° C

Heat released = 7020 J

Specific heat capacity of metal = ?

Solution:

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = 25.7°C - 90.5°C

ΔT = -64.8°C

7020 J = 120.7 g ×  c ×  -64.8°C

7020 J = -7821.36 g.°C ×  c

c = 7020 J / -7821.36 g.°C

c = 0.898 J/g.°C

Negative sign shows heat is released.

Answer:

A spatial pattern is a perceptual structure, placement, or arrangement of objects on Earth. It also includes the space in between those objects. Patterns may be recognized because of their arrangement; maybe in a line or by a clustering of points.

Explanation:

Answer:

Schistosoma or blood fluke

Explanation:

Parasitic organisms are defined as the organisms that depends on other organisms body called host for their nutrition and harm the host body.

The given image is of Schistosoma that is commonly known as blood flukes. Schistosoma are flatworms which causes group of infections in humans known as  schistosomiasis. Schistosoma is a water-borne parasite and found in veins near the human intestine.

Hence, the correct answer is "Schistosoma or blood fluke".

Answer:

1) The amount is less than one mole, 2) The jar is not completely filled, 3) We have 0.166 moles of sulfur.

Explanation:

We proceed to respond each question below:

1) Is this amount more or less than one mole?

According to the Avogadro's Number, one mole of an element contains about [tex]6.022\times 10^{23}[/tex] atoms. Given that we have [tex]1.000\times 10^{23}[/tex] atoms, then we conclude that this amount is less than one mole.

2) Place the jar underneath the counter. Was the jar completely filled?

Let suppose that the jar can contain up to a mole of sulfur. Then, we conclude that jar is not completely filled.

3) How many moles do you have?

The amount of moles is determined by dividing the current amount of atoms by Avogadro's Number:

[tex]x = \frac{1.000\times 10^{23}\,atoms}{6.022\times 10^{23}\,\frac{atoms}{mole} }[/tex]

[tex]x = \frac{500}{3011}\,mole[/tex]

We have 0.166 moles of sulfur.

Answer:

Mosquitos can stand on water because;

A. The mosquito is able to walk on the water due to the attraction between multiple water molecules, creating surface tension

Explanation:

Surface Tension is the surface property of a liquid which is due to the cohesive forces of attraction between its molecules, that enables it to withstand an external shearing force

The molecules in a liquid maintain a cohesive force between adjacent molecules that keeps all the molecules together such that the liquid has a defined volume

On the surface of the liquid, the cohesive forces between the molecules are shared by only between the adjacent molecules and molecules which are under the surface, and therefore, the attraction is much stronger such that the surface of the liquid is in tension, which is called the surface tension of the liquid

Therefore, the mosquito is able to walk on the water due to the attraction between multiple water molecules, creating surface tension.

Answer:

B. Controlled variables

Explanation:

The Dependent sample t-test compares the mean score of measurements in one group to that of another other group. It mainly used when analyzing comparable sample units as it pairs repeatable observations within a time frame.

Controlled variables are factors that are not tested and remain constant. Some examples of controlled variables are temperature, pressure, volume etc