Solve the problems. Express your answers to the correct number of significant figures. 2.31/0.790

97.22 grams of magnesium is needed.

Explanation:

The molar ratio of Mg to O2  to make MgO is 2:1

Here, we have 2 moles of O2, therefore we need 4 moles of Mg.

1 mol of Mg = 24.305 g

Therefore

4 moles of Mg = 4 [tex]\times[/tex] 24.305 g

                        = 97.22 g

Hence we need 97.22grams of magnesium are needed to completely reactwith 2.00 mol of O2 in the synthesis reaction that producesmagnesium oxide.

Answer:

A measuring balance can be used to find the mass of a wooden block.

Mass can simply be defined as the amount of matter which is present in an object. The mass of wooden objects is measured with a measuring balance such as the triple beam balance.

The object to be measured is placed in the left side of the balance. Then the mass is leveled off.

Answer:

3.59x10^21 molecules

Explanation:

1mole of a substance contains 6.02x10^23 molecules.

Therefore, 1mole of C8H18 will also contain 6.02x10^23 molecules

1mole of C8H18 = (12x8) +(18x1) = 96 + 18 = 114g.

1mole (i.e 114g) oh C8H18 contains 6.02x10^23 molecules.

Therefore, 0.68g of C8H18 will contain = (0.68 x 6.02x10^23)/114 = 3.59x10^21 molecules

To find the number of C8H18 molecules in 0.83 mL of C8H18 with a mass of 0.68 g, calculate the number of moles based on the molar mass and then multiply by Avogadro's number to get approximately 3.58 x 10^21 molecules.

To calculate the number of C8H18 molecules in 0.83 mL of C8H18 with a mass of 0.68 g, we can follow these steps:

Find the molar mass of C8H18. The molar mass of C8H18 (octane) is 114.23 g/mol.

Calculate the number of moles of C8H18 using the mass provided. Number of moles = mass / molar mass = 0.68 g / 114.23 g/mol.

Convert the number of moles to molecules using Avogadro's number (6.02 x 1023 molecules/mol).

The calculation will be as follows:

Number of moles = 0.68 g / 114.23 g/mol ≈ 0.00595 moles

Number of molecules = 0.00595 moles x 6.02 x 1023 molecules/mol ≈ 3.58 x 1021 molecules

Answer:

Explanation -

A Lewis electron dot symbol is a representation of the valence electrons around an atom that uses dot around the symbol of the element. Cations are formed when atoms lose electrons represented by fewer Lewis dots.

The Lewis Dot Diagram for a cation is a representation of the electron configuration after an atom loses one or more electrons. It shows the symbol of the atom with brackets and the number of valence electrons that have been removed.

The Lewis Dot Diagram for a cation is a representation of the electron configuration of the cation. In general, cations are formed when an atom loses one or more electrons, resulting in a positive charge. The Lewis Dot Diagram for a cation shows the symbol of the atom with brackets and the number of valence electrons that have been removed. For example, the Lewis Dot Diagram for a sodium cation (Na+) would show the symbol Na with brackets and the number 10 inside the brackets, indicating that one electron has been removed.

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Final answer:

Magnetic fields are depicted by magnetic field lines that indicate the direction and strength of the field around a magnet, which can be visualized with compasses or iron filings. The lines form closed loops and originate at the magnet's North pole, looping to the South pole.

Explanation:

Magnetic fields can be described and visualized through the use of magnetic field lines. These lines start at the North pole of a magnet and end at the South pole, forming closed loops that indicate the direction and strength of the magnetic field. To map out magnetic field lines, one might employ a small compass and trace the direction at multiple points around the magnet, or sprinkle iron filings to observe the lines directly. Magnetic field lines have specific properties, such as always forming closed loops and being tangent to the direction of the magnetic field at any given point.

In terms of visual representations, one commonly sees patterns where the field lines emerge from the North pole, loop around to the South pole, and continue through the magnet, indicating continuity. For electric currents, such as in a wire, the direction of the magnetic field can be determined using the right-hand rule, and it can be visualized using a circle of compasses or iron filings that align tangentially to the field lines created by the current.

Real-world examples include the Earth's magnetic field, which resembles the field of a giant bar magnet with a North and South pole, as well as the magnetic fields around solenoids and bar magnets shown through the distribution of iron filings.

Answer:

Attached.

Explanation:

I'm assuming Lewis structure is fine.

Cresol or trimethylhydroquinone, commonly known as 2,4,6-trimethylphenol, is an organic molecule with the chemical formula C9H12O. Because a hydroxyl group (-OH) is attached to a benzene ring, it is classified as a phenol.

The benzene ring serves as the main structural component of 2,4,6-trimethylphenol, which also has three methyl groups (CH) bonded to the carbon atoms at the 2, 4, and 6 positions. The chemical nomenclature, which refers to the exact locations of the substituents on the ring, is influenced by these methyl groups. At position 1, the hydroxyl group is attached to the benzene ring. 2,4,6-trimethylphenol is a phenolic chemical because it contains a hydroxyl group and exhibits some of the characteristics of phenols.

Learn more about benzene ring, here:

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Answer:

Molar mass of calcium is 40,078 g / mol

Explanation:

Molar mass (M) is the ratio of the mass to the mass of the substance and is expressed in grams per mole (g / mol).

The molar mass of a substance corresponds/it is equal to the relative atomic or relative molecular mass with the addition of the unit g/mol.

The relative atomic mass as well as the relative molecular mass are the basis for expressing the molar mass (M), the mass of one mole of a substance.

Answer:

260.34g

Explanation:

First, you need to know what angelic acid is comprised of. It is written as C₅H₈O₂.

In order to solve for the mass of 2.6 moles of angelic acid, you need the mass of 1 mole of angelic acid. This can be found by adding the masses from the periodic table, like shown below:

5 carbon atoms = (5)(12.01g) = 60.05g

8 hydrogen atoms = (8)(1.01) = 8.08g

2 oxygen atoms = (2)(16) = 32g

angelic acid = 60.05 + 8.08 + 32 = 100.13g

Then, set up a basic stoichiometric equation and solve. The units should cancel out.

[tex](\frac{2.6mol}{1} )(\frac{100.13g}{1mol} )=260.34g[/tex]

The mass in grams of 2.6 moles of angelic acid is 296.78 g.

To find the mass in grams of 2.6 moles of angelic acid, we need to use the molar mass of the compound. The molar mass of angelic acid is the sum of the atomic masses of all the elements present in the compound. According to the chemical formula of angelic acid (C6H10O2), the atomic masses of carbon, hydrogen, and oxygen are 12.01 g/mol, 1.01 g/mol, and 16.00 g/mol respectively.

So, the molar mass of angelic acid can be calculated as:

Molar mass = (6 x atomic mass of carbon) + (10 x atomic mass of hydrogen) + (2 x atomic mass of oxygen)

Molar mass = (6 x 12.01 g/mol) + (10 x 1.01 g/mol) + (2 x 16.00 g/mol)

Molar mass = 72.06 g/mol + 10.10 g/mol + 32.00 g/mol

Molar mass = 114.16 g/mol

The mass in grams of 2.6 moles of angelic acid can be calculated using the following conversion factor:

Mass (g) = Moles x Molar mass

Mass (g) = 2.6 moles x 114.16 g/mol

Mass (g) = 296.78 g

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Answer:

Choice A

Explanation:

Solvation describes the surrounding of solute ions by solvent molecules.

Final answer:

Solvation involves the intermolecular interactions of a solute with the surrounding solvent. In the case of ionic solutes, solvent molecules surround each ion and separate it from the rest of the solid. In the case of molecular solutes, each particle of the solute is surrounded by solvent particles, forming a solution. The correct option is A.

Explanation:

Chemically, a solvent will dissolve or "solvate" a solute. Solvation describes the intermolecular interactions of a molecule or ion in solution with the surrounding solvent. In the case of solvation in polar solvents, such as water, solvent molecules surround each ion of the ionic solute and separate it from the rest of the solid. This process is also referred to as hydration. On the other hand, in the case of solvation of a molecular solute like sucrose, each particle of the solute is surrounded by particles of the solvent, forming a solution.

D

Make sure the results of the experiment are useful

Explanation:

In an experiment, certain variables (independent variables) are controlled to check how they affect other variables (dependent variables) and understand the relationship between them. Also, these experiments usually have a control experiment, of no change, to help compare results and increases their reliability.

Final answer:

To calculate the number of moles of CO2 present in 11 grams of CO2, divide the mass of CO2 by the molar mass of CO2.

Explanation:

To calculate the number of moles of CO2 present in 11 grams of CO2, we need to use the molar mass of CO2, which is 44 g/mol. We can set up the calculation as follows:

Number of moles = Mass of CO2 / Molar mass of CO2

Number of moles = 11 g / 44 g/mol

Number of moles = 0.25 mol

Therefore, there are 0.25 moles of CO2 present in 11 grams of CO2.

Answer:

3 moles of [tex]Cl^{-}[/tex] is needed for [tex]Na^{+}[/tex]to be fully consumed.

Explanation:

For the balanced equation:

                                  [tex]Na^{+} + Cl^{-}[/tex]  ⇒  [tex]NaCl[/tex]

First, find the moles of Na corresponding to the 69g used the general definition of mol:

                               [tex]mol Na^{+} = \frac{69 g}{23 g/mol } = 3mol[/tex]

We observe that the equation is balanced and the stoichiometric ratio between them is 1: 1.

According to this, one mole of Na will react with one mole of Cl.

                3 moles of [tex]Cl^{-}[/tex] is needed for [tex]Na^{+}[/tex]to be fully consumed.

Final answer:

To react 69 g of sodium with chlorine to produce sodium chloride, 1.5 moles of chlorine gas are required, following the stoichiometry from the balanced chemical equation 2 Na(s) + Cl₂(g) → 2 NaCl(s)

Explanation:

The student is asking for the number of moles of chlorine needed to react with 69 g of sodium to produce sodium chloride, given the balanced chemical equation:

Balance the Reaction:

2 Na(s) + Cl₂(g) → 2 NaCl(s)

Calculate Moles of Sodium:

First, we need to calculate the number of moles of sodium. The molar mass of sodium (Na) is 22.99 g/mol. Therefore, the number of moles of sodium in 69g is:

moles Na = mass Na / molar mass Na = 69g / 22.99 g/mol = 3 moles (rounded to two significant figures)

Determine Moles of Chlorine:

Using stoichiometry from the balanced equation, 2 moles of sodium react with 1 mole of chlorine. Therefore, if we have 3 moles of sodium, we would need:

moles Cl₂ = moles Na / 2 = 3 moles / 2 = 1.5 moles of Cl₂
Therefore, 1.5 moles of chlorine gas are required to react with 69 g of sodium to produce sodium chloride. This stoichiometry is consistent regardless of the mass of sodium you start with, as long as you're using the correct molar mass to convert grams to moles.

The answer is likely to be A

Answer: The awnser us B

Explanation: Because both of the temperatures for condensing and freezing are the same thing 32 degrees.

Answer:

Nitrogen has an atomic number of 7

Explanation:

Answer:

14

Explanation:

nucleon number= number of protons+ number of neutrons

Answer:

Mass is the measure of the amount of matter in an object. We see that the gravitational force between objects increases as the masses of the objects increase. With distance, we see that the strength of gravity decreases if the distance between two objects increases.

Explanation:

The amount of gravity affecting an object depends on two things: the masses of the objects being attracted and the distance between the objects. Mass is the measure of the amount of matter in an object. ... With distance, we see that the strength of gravity decreases if the distance between two objects increases

Final answer:

Mass, distance, and gravity are interconnected in physics through Newton's law of gravitation.

Explanation:

The relationship between mass, distance, and gravity is described by Newton's law of universal gravitation. This law states that every point mass attracts every other point mass by a force acting along the line intersecting both points. This force is directly proportional to the product of the masses of the two objects and inversely proportional to the square of the distance between their centers.

Mathematically, the force of gravity (F) between two objects with masses m1 and m2 separated by a distance r is given by:

F = G * (m1 * m2) / r^2

where G is the gravitational constant, approximately equal to 6.674 × 10^-11 N m^2/kg^2.

From this equation, we can see that:

1. The force of gravity (F) is directly proportional to the product of the masses (m1 * m2). This means that if the masses of the objects increase, the force of gravity between them also increases.

2. The force of gravity (F) is inversely proportional to the square of the distance (r^2) between the centers of the objects. This means that as the distance between the objects increases, the force of gravity between them decreases rapidly.

Answer:

c

Explanation:

Answer:

A(net)

Explanation:

Answer:

0.48L of NaOH

Explanation:

Data obtained from the question include:

Number of mole of NaOH = 0.725mol

Molarity of NaOH = 1.50M

Volume of NaOH =?

Molarity = mole /Volume

Volume = mole /Molarity

Volume = 0.725/1.5

Volume = 0.48L

Therefore, 0.48L of NaOH is needed for the reaction

Answer: M = 2.08 M

Explanation: Molarity is expressed as the number of moles per unit volume in liters. First convert the mass of HCl to moles using its molar mass. Then substitute the variables to the formula for molarity.

75.00 g HCl x 1 mole HCl / 36 g HCl

= 2.08 moles HCl

For Molarity.

M = n / L

= 2.08 moles HCl / 1.000 L

= 2.08 M

Answer:

C,A

Explanation:

Answer:

c and a

Explanation:

Final answer:

In the transformation of electrical energy to sound and light by a television set, some energy is lost as heat due to the inefficiency of the device.

Explanation:

A television set changes electrical energy into sound and light energy. During this energy transformation process, some energy is usually lost as heat. This loss is primarily due to the inefficiency of electrical devices, where not all the incoming electrical energy is converted into the desired forms of energy.

The excess energy frequently dissipates as heat, which is released into the surroundings. This process aligns with the laws of thermodynamics, specifically the second law, which states that energy transformations are never 100% efficient.

Answer:

24.42 J/K

Explanation:

i got it right

Answer:

d

Explanation:

The correct answer is 50% of her eggs will carry the allele B, and the remaining 50% will carry the allele b.

If a woman has the genotype Bb for eye color, where B represents the dominant allele for brown eyes and b represents the recessive allele for blue eyes, each of her sex cells (eggs or ova) will have one of the two possible alleles, either B or b.

During the process of meiosis, which is the cell division that produces gametes (sex cells) in humans, the two alleles for a particular gene separate and end up in different gametes.

Specifically, in the case of this woman with the genotype Bb:

1. During meiosis, the homologous chromosomes carrying the alleles for eye color will separate, resulting in two different types of gametes (eggs).

2. Half of her eggs will contain the allele B (for brown eyes), and the other half will contain the allele b (for blue eyes).

Therefore, if a woman has the genotype Bb (brown eyes with the recessive allele for blue eyes), each of her sex cells (eggs) will have either the allele B or the allele b, but not both.

In other words, 50% of her eggs will carry the allele B, and the remaining 50% will carry the allele b.

This is known as the law of segregation, which states that during gamete formation, the two alleles for a particular gene separate, and each gamete receives only one of the two alleles.

Answer:

In an endothermic reaction, products are higher than reactants in potential energy and  less stable

Explanation:

An endothermic reaction is a reaction that needs energy to happen. The energy needed from the endothermic reaction is taken from the system. In this reaction, the reactant will absorb the energy so they will make a product with higher energy.  

Since energy moves from a higher potential to lower potential, the product of the endothermic reaction is less stable.

Answer: m = 11.2 g C7H16

Explanation: First convert the mass of CO2 to moles. Then do the mole ratio between CO2 and C7H16 which is 7:1. Finally convert the moles of C7H16 to the mass of C7H16.

Solution attached.

The grams of heptane were burned is 88.8 grams .

The balanced reaction equation for the combustion of heptane, C7H16, is:

C7H16 + 11O2 → 7CO2 + 8H2O

To find out how many grams of heptane were burned, we can use the stoichiometry of the reaction. The molar ratio between heptane and CO2 is 1:7. So, we can set up a simple proportion to solve the problem.

Let 'x' be the mass of heptane:

(34.5g CO2) / (44.01g/mol CO2) = x / (114.22g/mol heptane)

Using this formula, we find that x = 88.8g. Therefore, 88.8 grams of heptane were burned.

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The balanced equation is given as, 1 CS₂ + 3 O₂ → 1 CO₂ + 2 SO₂

Explanation:

CS₂ + O₂ → CO₂+ SO₂

Atoms       Before balancing          After balancing

                  LHS        RHS              LHS          RHS

C                 1               1                    1                1

S                  2              1                     2                2  

O                  2              4                    6                2+4=6

First we have to put 2 in front of SO₂, so the number of S atoms becomes equal on both sides, but the number of O- atoms gets increased as 6 on RHS, to balance that we have to put 3 infront of O₂, so that every atom on both sides of the equation gets balanced.

So the balanced equation is

1 CS₂ + 3 O₂ → 1 CO₂ + 2 SO₂

Answer:

The amount of sample remain  after 48 years is 12.5 g.

Amount of sample decayed = 100 g- 12.5 g = 87.5 g

Explanation:

Given data:

Half life of Pu²⁴¹ = 14 years

Total amount of sample = 100 g

Sample remain after 42 years = ?

Sample decayed = ?

Solution:

First of all we will calculate the number of half lives.

Number of Half lives = T elapsed / half life

Number of Half lives = 42 years / 14 years

Number of Half lives = 3

At time zero = 100 g

At first half life = 100 g /2 = 50 g

At second half life = 50 g/2 = 25 g

At third half life = 25 g/ 2 = 12.5 g

So the amount of sample remain  after 48 years is 12.5 g.

Amount of sample decayed = 100 g- 12.5 g = 87.5 g

Answer:

See the answer beloew, please.

Explanation:

The concepts of heat and temperature are related, but they are not the same. Temperature refers to a physical quantity which indicates the amount of heat. The latter corresponds to the energy that moves from one body to another, thus being able to raise or lower the temperature.

Final answer:

Heat refers to the transfer of thermal energy, measured in joules, while temperature measures the kinetic energy of particles, observed via a thermometer. Temperature influences chemistry by affecting states of matter and reaction rates.

Explanation:

Many often confuse heat with temperature, yet they refer to different aspects of thermal energy. Temperature is a measure of the average kinetic energy of the particles in a substance and is what we measure with a thermometer. On the other hand, heat is the transfer of thermal energy due to a temperature difference between objects. It is a form of energy flow from a warmer object to a cooler one and is measured in joules or calories. A high temperature might make us feel 'hot', but it is the flow of heat to or from our bodies that we truly sense.

Temperature plays a critical role in chemistry; it affects the state of matter and the rate of chemical reactions. For instance, when ice turns into water, it is because of an increase in temperature. Similarly, many chemical reactions speed up with higher temperatures, and keeping unstable materials like enzymes at lower temperatures can prolong their stability.

Answer:

Sodium has 496KJ/mol ionization energy.

Explanation:

Ionization energy is the process in which electron which is present in the outermost shell is removed with the absorption of energy by the electron. Different atoms have different ionization energies. When we go from left to the right in the periodic table, ionization energy increases due to atomic size decrease. When we go from top to bottom in the periodic table, ionization energies decreases due to increase the atomic size. Sodium has 496KJ/mol ionization energy which means the outermost electron needs 496KJ/mol energy for removal.

Final answer:

Sodium, with atomic number 11, has 11 ionization energies, each corresponding to one of its 11 electrons. The first ionization energy involves removing the loosely held valence electron, resulting in the formation of a sodium ion (Na+). Each subsequent ionization energy is higher due to greater electrostatic attraction after each electron removal.

Explanation:

For an element such as sodium, the number of ionization energies corresponds to the number of electrons an atom has, which is 11 for sodium. Each removal of an electron from an atom requires more energy than the last due to the increased electrostatic attraction between the remaining electrons and the nucleus. This means for sodium there are 11 ionization energies, each removal corresponding to one of sodium's electrons - starting with the outermost electron, which is in the 3s orbital.

The first ionization energy is typically the smallest because it involves removing the most loosely held electron. As you proceed to remove more electrons, the ion becomes more positively charged and the remaining electrons are more strongly attracted to the nucleus. Hence, each successive ionization energy is greater than the previous one, often with a significant jump observed when starting to remove core electrons that are closer to the nucleus and more tightly bound.

The alkali metal sodium, with atomic number 11, has an electronic configuration of [Ne]3s¹. This 3s electron is the valence electron and is the easiest to remove. Once this electron is removed, sodium becomes a sodium ion (Na+) with a +1 charge.

Answer:

B

Explanation:

well it can be D cause doubling the water wont fix things for the future and may not be done. C wont fix it cause you arent solving the problem jus holding it off and it cant A causing dumping bad stuff into the lake started the problem. Its deff B

Answer:

8.31moles of H2O

Explanation:

Avogadro's hypothesis gives us an excellent understanding that 1mole of any substance contains 6.02x10^23 molecules. This means that 1mole H2O also contains 6.02x10^23 molecules.

Now, if 1 mole of H2O contains 6.02x10^23 molecules

Therefore, Xmol of H2O will contain 5.00x10^24 molecules i.e

Xmol of H2O = (5.00x10^24)/6.02x10^23 = 8.31moles of H2O