what is the usual composition of acid etch?

Answer:

Choice A. 0.50 g.

Explanation:

According to the question, the reaction here converts

to

By the Law of Conservation of Mass, matter can neither be created nor destroyed in a chemical reaction. (Shrestha et. al, Introductory & GOB Chemistry, Chemistry Libretexts, 2019.)

In other words, the mass of the reactants, combined, shall be the same as the mass of the products, combined.

What's the mass of the reactants?

[tex]\rm \underbrace{\rm 3.80\;g}_{\mathrm{Cs_2CO_3}} + \underbrace{\rm 1.90\; g}_{\mathrm{HBr}} = 5.70\;g[/tex].

What's the mass of the products?

Let [tex]m(\mathrm{CO_2})[/tex] represent the mass of carbon dioxide produced in this reaction.

The mass of the products will be:

[tex]\rm \underbrace{\rm 5.20\;g}_{\mathrm{CeBr}\text{ and }\mathrm{H_2O}} + \underbrace{m(\mathrm{CO_2})}_{\mathrm{CO_2}}[/tex].

The two masses shall be equal. That is:

[tex]\rm 5.20\; g + \mathnormal{m}(\mathrm{CO_2}) = 5.70\;g[/tex].

[tex]m(\mathrm{CO_2}) = \rm 0.50\;g[/tex].

In other words, by the Law of Conservation of Mass, the mass of carbon dioxide produced in this reaction will be [tex]\rm 0.50\;g[/tex].

Answer:

b. LD-75

Explanation:

You give the same dosage of chemicals A and B to a sample of test subjects.

Chemical A kills 75 % of the subjects, while chemical B kills only 25 %.

Chemical A, with LD-75, is more toxic.

LD-75 would be more toxic. Hence, option B is correct.

The quality of being toxic or poisonous.

You give the same dosage of chemicals A and B to a sample of test subjects.

Chemical A kills 75 % of the subjects, while chemical B kills only 25 %.

Chemical A, with LD-75, is more toxic.

Hence, option B is correct.

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Answer:

A

Explanation:

CH4+O2-CO2+ H20

that mean methane has burn in oxygen to produce CO2

Answer:

Water supply

Explanation:

When there is drought, which happens mostly within the tropics, water sources go dry. Plants and animals suffer alike. Animals have to scramble for the limited amount of water to quench their thirsts. Water is one of the basic requirements for the survival of living organisms like animals.

Answer:

water supply

Explanation:

Answer:

D

Explanation:

Gases move away from each other. Solids and liquids are more attached whereas gases are separate

The true statement about gas particles is that "Gas particles are farther apart and have weaker attraction between them than the particles in a solid"

STATES OF MATTER:

There are three states of matter in existence namely:

Therefore, the true statement about gas particles is that "Gas particles are farther apart and have weaker attraction between them than the particles in a solid"

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Answer: 0.245 moles of oxygen must be placed in the container to exert the given pressure at the given temperature. The Ideal Gas Law equation gives the relationship among the pressure, volume, temperature, and moles of gas.

Further Explanation:

The Ideal Gas Equation is:  

[tex]PV = nRT[/tex]  

where:  

P - pressure (in atm)  

V - volume (in L)  

n - amount of gas (in moles)  

R - universal gas constant [tex]0.08206 \frac{L-atm}{mol-K}[/tex]  

T - temperature (in K)  

In the problem, we are given the values:  

P = 2.00 atm (3 significant figures)

V = 3.00 L  (3 significant figures)

n = ?

T = 25.0 degrees Celsius (3 significant figures)  

We need to convert the temperature to Kelvin before we can use the Ideal Gas Equation. The formula to convert from degree Celsius to Kelvin is:  

[tex]Temperature \ in \ Kelvin = Temperature\ in \ Celsius \ + \ 273.15[/tex]  

Therefore, for this problem,  

[tex]Temperature\ in \ K = 25.0 +273.15\\Temperature\ in \ K = 298.15[/tex]  

Solving for n using the Ideal Gas Equation:  

[tex]n \ = \frac{PV}{RT}\\n \ = \frac{(2.00 \ atm) \ (3.00 \ L)}{(0.08206 \ \frac{L-atm}{mol-K})( 298.15 \ K)}  \\n \ = 0.245 \ mol[/tex]

The least number of significant figures is 3, therefore, the final answer must have only 3 significant figures.

Learn More  

1. Learn more about Boyle's Law https://brainly.com/question/1437490  

2. Learn more about Charles' Law https://brainly.com/question/1421697  

3. Learn more about Gay-Lussac's Law https://brainly.com/question/6534668

Keywords: Ideal Gas Law, Volume, Pressure

Answer:

answer in picture

Explanation:

First you divide each mass by the mass number of the element:

Cobalt        1.216 / 59 = 0.02

Oxygen      0.495 / 32 = 0.03

Then the result is divided by the lowest number:

Cobalt        0.02 / 0.02 = 1

Oxygen      0.03 / 0.02 = 1.5

After that you multiply with a number to obtain an integer number:

Cobalt        1 × 2 = 2

Oxygen      1.5 × 2 = 3

The empirical formula of the oxide:  

Co[tex]_{2}[/tex]O[tex]_{3}[/tex]

Answer:

A. covalent, polar

Explanation:

Water is a(n) covalent molecule, and it easily dissolves polar molecules.

Answer:

Fr

Explanation:

Ca (calcium) has 1.00

Sr (strontium) has 0.95

and Fr (francium) has 0.7

making it Fr (francium)

Answer:

A) Alloys are mixtures with undefined proportions.

Explanation:

Alloys are different mixtures or different materials with no exact portion size.  

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Answer:

Approximately 53.3  %.

Explanation:

Molar mass of C2H4O2

= 2 * 12.011 + 4 * 1.008 + 2 * 15.999

=  60.052

% oxygen = (31.998* 100) / 60.052 = 53.28 %

a. They are both normally found as gases in the atmosphere.  TRUE

That is correct, the oxygen and nitrogen are found in large quantities in the air around us.

b. They can be either liquids or gases. TRUE

Under certain temperatures any gas will transform into a liquid.

c.They turn from gas to liquid at the same temperature. FALSE

Oxygen it will pass into a liquid at -183 °C while nitrogen pass into a liquid at -195.8 °C.

d.They can be changed from gases to liquids by heating them. FALSE

The gases change to liquids by cooling them.

Oxygen and nitrogen are normally found as gases in the atmosphere, and they can be changed from gases to liquids by heating them.

Two statements are true about oxygen and nitrogen:

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Answer:

0.666 mol I

Explanation:

0.333 mol CaO(IO₃)₂ × (2 mol IO₃ / mol CaO(IO₃)₂) = 0.666 mol IO₃

0.666 mol IO₃ × (1 mol I / mol IO₃) = 0.666 mol I

Answer:

5.64×10²³ atoms C

Explanation:

Convert moles of H to moles of C:

2.81 mol H × (2 mol C / 6 mol H) = 0.937 mol C

Convert moles of C to atoms of C:

0.937 mol C × (6.02×10²³ atoms C / mol C) = 5.64×10²³ atoms C

Answer:

No reaction.

Explanation:

An Arrhenius base (like NaOH) increases the concentration of hydroxide ions present in the solution.

If you add Rb to an aqueous solution of NaOH, you will get an explosion.

However, the Rb does not react with the OH^-. Instead, it reacts rapidly with the water.

2Rb + 2H2O → 2RbOH + H2

So much heat is generated that the hydrogen explodes:

2H2 + O2 → 2H2O

Answer:

0.0447 moles of Aluminum

Explanation:

Break this down to an ionic equation (which may not exist in the real world but it will give you the mol ratios).

Al2(SO4)3 ===> 2Al^(+3) + 3 SO4^(-2)

Now write the equation showing the actual number of moles of SO4^(-2) present. Indicate the Al moles with an x

Al2(SO4)3 ===> 2Al^(+3) + 3 SO4^(-2)

                                x             0.0670  

Now set  up a proportion

2/x = 3/0.0670                             Cross multiply

2*0.0670 = 3x                              Simplify the left

0.134 = 3x                                     Divide both sides by 3

0.134/3 = 3x/3                              Divide

0.0447 = x

there are 0.0447 moles of Aluminum

Answer: The volume of gas is 24.9 L. The volume can be calculated using the Ideal Gas Equation which relates the pressure, volume, temperature, and amount of gas to each other.  

Further Explanation

The Ideal Gas Equation is:  

[tex]PV = nRT[/tex]

where:

P - pressure (in atm)

V - volume (in L)

n - amount of gas (in moles)

R - universal gas constant [tex]0.08206 \frac{L-atm}{mol-K}[/tex]

T - temperature (in K)

In the problem, we are given the values:

P = 0.80 atm (2 significant figures)

V =  ?

n = 0.75 moles (2 significant figures)

T = 50.0 degrees Celsius (3 significant figures)

We need to convert the temperature to Kelvin before we can use the Ideal Gas Equation. The formula to convert from degree Celsius to Kelvin is:

[tex]Temperature \ in \ Kelvin = Temperature\ in \ Celsius \ + \ 273.15[/tex]

Therefore, for this problem,

[tex]Temperature\ in \ K = 50.0 +273.15\\Temperature\ in \ K = 323.15[/tex]

Solving for V using the Ideal Gas Equation:

[tex]V = \frac{nRT}{P} \\V = \frac{(0.75\ mol) \ (0.08206 \ \frac{L-atm}{mol - K}) \ (323.15\ K) \ }{0.80 \ atm} \\V = 24.86\ L[/tex]

The least number of significant figures is 2, therefore, the final answer must have only 2 significant figures.  Hence, the volume is 24.9 L.

Learn More

1. Learn more about Boyle's Law https://brainly.com/question/1437490  

2. Learn more about Charles' Law https://brainly.com/question/1421697

3. Learn more about Gay-Lussac's Law https://brainly.com/question/6534668

Keywords: Ideal Gas Law, Volume, Pressure

The volume of a gas at 50.0°C and 0.80 atm, with 0.75 moles of the gas present, is 24.93 L.

The volume of a gas can be calculated using the ideal gas law equation, PV = nRT, where P is the pressure, V is the volume, n is the number of moles of gas, R is the ideal gas constant, and T is the temperature in Kelvin. To calculate the volume, we can rearrange the equation to V = (nRT/P).

Using the given values, n = 0.75 moles, R = 0.08206 L-atm/mol-K, T = 50.0°C + 273.15 = 323.15 K, and P = 0.80 atm, we can plug them into the equation:

V = (0.75 mol x 0.08206 L-atm/mol-K x 323.15 K) / 0.80 atm = 24.93 L

Volume is a measure of the amount of space occupied by a three-dimensional object. It is typically measured in cubic units, such as cubic meters or cubic centimeters. The volume of an object can be calculated using various formulas, depending on the shape of the object. For example, the volume of a cube can be calculated using the formula V = s^3, where V is the volume and s is the length of one side of the cube. Similarly, the volume of a cylinder can be calculated using the formula V = πr^2h, where V is the volume, r is the radius of the base of the cylinder, and h is the height of the cylinder.

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Answer:

280 mL

Explanation:

Ideal gas law:

PV = nRT

Rearranging:

V / T = nR / P

At constant pressure:

V₁ / T₁ = V₂ / T₂

Substituting values:

250 / (15 + 273) = V / (45 + 273)

V = 276

Rounded to two significant figures, the volume will be 280 mL.

When using the ideal gas law, remember to always use absolute units for temperature, like Kelvin.

Final answer:

The volume of oxygen, initially at 250 ml and 15 degrees Celsius, will increase to approximately 275.5 ml when the temperature is raised to 45 degrees Celsius, according to Charles's Law.

Explanation:

The volume of a quantity of oxygen gas changes with temperature, which can be explained by Charles's Law. This law states that at constant pressure, the volume of a gas is directly proportional to its absolute (Kelvin) temperature. To find the new volume at a higher temperature, you can use the formula V₁/T₁ = V₂/T₂, where V₁ and T₁ are the initial volume and temperature, and V₂ and T₂ are the final volume and temperature.

To apply this to the student's question: The oxygen has an initial volume (V₁) of 250 ml at an initial temperature (T₁) of 15 degrees Celsius, which converts to 288.15 K (Celsius to Kelvin: C + 273.15). The final temperature (T₂) is 45 degrees Celsius or 318.15 K. Applying Charles's Law, we get:

250 ml / 288.15 K = V₂ / 318.15 K

Multiplying both sides by 318.15 K to solve for V₂ gives us:

V₂ = (250 ml * 318.15 K) / 288.15 K

V₂ ≈ 275.5 ml

So, when the temperature is raised to 45 degrees Celsius, the volume of oxygen will be approximately 275.5 ml.

Answer:

D. The nucleus of an atom of lithium splits, resulting in smaller fragments and the release of a large amount of energy.

Explanation:

Fission is the splitting of a nucleus, so this is the only option that involves fission.

A is wrong. Li atoms do not bond to form molecules. Instead, the nuclei are immersed in a sea of electrons.

B is wrong. The joining of two nuclei is fusion.

C is wrong. Adding an electron to an atom of lithium is not a nuclear reaction.

The nucleus of an atom of lithium splits, resulting in smaller fragments and the release of a large amount of energy. Therefore, option D is the correct answer.

Nuclear fission is a reaction in which a heavy nucleus splits into two or more smaller nuclei. Some characteristics features of nuclear fission are,

Thus, we can conclude that, in nuclear fission lithium atom is splits into smaller fragments with the release of a large amount of energy. Therefore, option D is the correct answer.

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Answer:

See below

Explanation:

Ca + 2H2O → Ca(OH)2 + H2

The elements involved are:

The numbers of each atom are:

The 2 in front of H2O multiplies everything in the H2O.

Answer:

One positive charge

Explanation:

In a neutral atom, the number of positive and negative particles are equal. This leaves the atom with a net charge of zero, 0.

When the number of protons in an atom is greater than the number of electrons, the atom becomes positively charged. When an atom loses an electron when a bond wants to form, it has a net positive charge.

The number of electrons lost or gained determines the charge.

Answer:

A - 8

B - 8

C - O

D - 26

E - 30

F - Fe

Explanation:

Use these things:

1. A = Z + N,

where A - mass number,

Z - atomic number,

N - number of neutrons

2. atomic number = number of protons

Answer:

CaCl₂(s) ⟶ Ca²⁺(aq) + 2Cl⁻(aq)

Explanation:

When the calcium chloride dissolves. the calcium and chloride ions leave the surface of the solid and go into solution as hydrated ions.

Answer:

1.1724 g.

Explanation:

The molecular mass of 1.0 mol (MgSO₄.7H₂O) = 246.4 g/mol.

The molecular mass of pure MgSO₄ = 120.366 g/mol.

The molecular mass of 7(H₂O) = 7(18.0 g/mol) = 126.0 g/mol.

∴ The mass % of pure MgSO₄ = [(mass of pure MgSO₄)/(mass of MgSO₄.7H₂O)] x 100 = [(120.366 g/mol)/(246.4 g/mol)] x 100 = 48.85%.

∴ the quantity of pure MgSO₄ = (mass of MgSO₄.7H₂O)(% of MgSO₄/100) = (2.4 g)(48.85/100) = 1.1724 g.

Answer:

0.187kg

Explanation:

Given parameters:

Percentage compostion of bauxite in ore = 54%

Mass of ore = 1kg

Unknown:

Mass of Al that can be extracted from the ore = ?

Solution

Bauxite is an ore of Aluminium. It is made up of several minerals from with aluminium can be extracted in economic amount. Some of these minerals are gibbsite, boehmite, diaspore etc. Let us assume that the ore we are dealing with contains chiefly gibbsite.

The formula of Gibbsite is Al(OH)₃

We know that 54% of the ore is made up of bauxite and the remaining 46% of the ore will form the gangue(not useful part of the ore)>

Let us find the mass of the bauxite contained in the ore:

  Mass of bauxite = [tex]\frac{54}{100}[/tex] x 1kg = 0.54kg

Since we know the mass of bauxite in the ore now, we can estimate the mass of the aluminium in the ore.

First, we find the molar mass of the gibbsite:

Molar mass of Al(OH)₃ = 27 + 3(16 + 1) = 78gmol⁻¹

Atomic mass of aluminium is 27

Mass of aluminium that could be extracted = [tex]\frac{27}{78}[/tex] x 0.54

                                                                       = 0.346 x 0.54

                                                                       = 0.187kg

Answer:

Explanation:

One of the assumptions of the kinetic molecular theory is that the gas particles are way smaller than the separtion between them and, in consequence, most of the volume in a gas is empty space.

This condition (that most of the volume in a gas is empty space) explains why the gases can be easily compressed: since there are vast unoccupied spaces when the pressure is increased, the particles can approach each other with which the total volume of the gas decreases.

Expandibility, the property of expanding, is the ability that gases have to occupy the entire space of the container in which they are located. The particles then will get separated leaving most of the space empty.

The fact that most of the volume in a gas is empty space means that the volume for a certain amount of particles is much larger than the volume that the same number of particles in a solid will occupy, driving to much lower densities.

Gases exhibit very low density, the ability to mix completely with other gases, and follow Avogadro's hypothesis, all of which support the assumption that a gas is mostly empty space.

Properties of Gases and Empty Space

The properties of gases we observe can indeed support the assumption that most of the volume of a gas is empty space. One key property is the fact that gases have a very low density compared to liquids and solids. This low density occurs because the gas particles, which have mass, make up only a tiny fraction of the gas's volume. The rest is empty space that can be compressed or expand when the pressure or temperature changes.

Another supportive property is the ability of gases to mix completely with one another, without any significant interference from the size of their particles. This behavior also indicates that there is a lot of space between particles, allowing them to move freely and intermingle.

Moreover, Avogadro's hypothesis suggests that equal volumes of all gases, at the same temperature and pressure, contain equal numbers of molecules, thus underscoring the concept of empty space in gases since these molecules occupy negligible space compared to the whole volume.

B. 3.62 m3

PV = nRT

(0.1185 atm)V = (17 mol)(0.0821 L•atm/K•mol)(307.15 K)

0.1185V = 428.689

V = 3617.63 L

so for cubic meters, 1,000 liters equals 1 m^3. Simply divide the answer by 1,000.

The volume that this would occupy is 3.62 m^3.

volume is the measure of the capacity that an item holds. for example, if a cup can hold one hundred ml of water up to the brim, its volume is said to be one hundred ml. volume also can be defined as the amount of area occupied by a three-dimensional object.

volume refers to the amount of area the object takes up. In other words, volume is a measure of the size of an object, just like height and width are methods to describe size. If the object is hollow (in other words, empty), volume is the amount of water it can hold.

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Answer: Option (C)

Explanation: Hydrogen and Helium initially, both were present on the earth's atmosphere. But later they were reduced upto a huge extent. Due to the location of earth near to the sun, these gases must have evaporated from the earth's atmosphere. At present the amount of hydrogen and helium is very less.

Thus, the correct answer is option (C).

Answer:

Explanation:

Since, the atomic mass of the elements is a characteristic property of the elements, you can use the data given, number of moles and mass in grams of the product, to calculate the atomic mass of the product, and then compare with the atomic masses of the elements (information foun in any periodic table).

1) Atomic mass of the product:

2) Periodic table:

3) Conclusion:

So, you can conclude safely that the element you have produced is Molybdenum.

In order for heat transfer between bodies from one container to another, one sample must be cooler than the other.

When there is a temperature difference between two substances , energy flows in the form of heat from the warmer to the cooler body until the temperature of both the body reaches equilibrium or same. This process is commonly known as heat transfer.This is according to second law of thermodyanimcs

In summary, heat flows due to a temperature gradient or temperature difference . The substance at a higher temperature will lose energy while the substance at a lower temperature gains energy in the form of heat. This flow continues until both the body reaches an equal temperature

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