A lab director asks two students, Lydia and Damien, to each select a bottle of a concentrated weak base. When they reach the
cabinets, they find different chemical solutions with varying concentrations. All of the options are bases. Which bottles should they choose?

Lydia should select the bottle of _______. Damien should select the bottle of ________

Final answer:

To produce 10g of magnesium oxide, 6g of magnesium would be needed.

Explanation:

To find the mass of magnesium needed to produce 10g of magnesium oxide, we can use the given information about the reaction between magnesium and oxygen. From the given information, we know that when 24g of magnesium is heated in air, 40g of magnesium oxide is produced. This means that the reaction produces a 1:1 ratio between the mass of magnesium and the mass of magnesium oxide. Therefore, if 24g of magnesium produces 40g of magnesium oxide, then 10g of magnesium oxide would require (10g/40g) * 24g = 6g of magnesium.

Answer:

the earth

Explanation:

because the moon is blocking the light of the sun

Pangaea was a supercontinent. It is the last supercontinent that had all of the continental masses joined as one, though after its breaking apart there were two other supercontinents which were very short lasting. This supercontinent formed from the pre-existing continental masses that moved toward one another and merged by the late Paleozoic era, approximately around 335 million years ago. Pangaea existed until the early Mesozoic era, and it started to break apart around 175 million years ago. From the breaking apart of this supercontinent, initially formed Laurasia and Gondwanaland, and from the further breaking apart of these two we got the modern day continents.

Answer:

pOH = 8.02

Explanation:

Given:

[OH-] concentration for HNO3 solution = 9.50*10^-9 M

To determine:

pOH of the above solution

Explanation:

pOH of a given solution refers to the concentration of OH- ions i.e. the degree of basicity of that solution

[tex]pOH = -log[OH-]\\\\For\ the \ HNO3\ solution:\\\\pOH = -log(9.50*10^{-9}) = 8.02[/tex]

Answer:

berm

a berm can be somethint in the middle or water and you can see it once the water go down oe dryes

Answer:

2

Explanation:

Answer:

Pb + 2AgNO3 --->   Pb(NO3)2 + 2Ag

Explanation:

The lead Pb2+ ion has a valency of 2 and therefore combines with 2 nitrate ions (NO3)-..

[tex]Pb + 2AgNO_3[/tex]  →  [tex]Pb(NO_3)_2 + 2Ag[/tex]

An equation that has an equal number of atoms of each element on both sides of the equation is called a balanced chemical equation.

[tex]Pb + 2AgNO_3[/tex]  →  [tex]Pb(NO_3)_2 + 2Ag[/tex]

This is the balanced chemical equation. Where there are 1 Pb, 2 Ag, 2N, and 6 oxygen atoms on both sides.

Learn more about the chemical equation here:

https://brainly.com/question/15052184

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The mass of oxygen atoms in 1 mole of water is 16 grams.

This can be calculated by looking at the molecular formula of water, which is H2O. From this formula, we know that one molecule of water contains two hydrogen (H) atoms and one oxygen (O) atom.

Given that the molar mass of hydrogen is 1 gram/mole and the molar mass of oxygen is 16 grams/mole, we can determine that the mass ratio of hydrogen to oxygen in a water molecule is 2:1.

Therefore, in 1 mole of water, we have 2 moles of hydrogen atoms and 1 mole of oxygen atoms.

Multiplying the molar mass of oxygen (16 grams/mole) by the number of moles (1 mole) gives us a mass of 16 grams for the oxygen atoms in 1 mole of water.

Answer:

b) the oxygen atom of one molecule and a hydrogen atom of an adjacent molecule

Explanation:

In a H₂O molecule there are two O-H bonds. The O atom being more electronegative pulls away the shared pair of electron in the covalent bond more towards itself thus O gaining a partial negative charge and H atom getting a partial positive charge. Thus a dipole exists in the O-H bond in the H₂O molecules. Thus in both liquid water and solid ice there is a weak attraction or hydrogen bond between the oxygen atom of one H₂O molecule and a hydrogen atom of an adjacent H₂O molecule.

Answer:

100 mL Graduated cylinder.

Explanation:

The instrument would give the greatest precision is 100 mL Graduated cylinder.

Because it has the smallest diameter and it is graduated every 1.0 mL. so, its error percent is the lowest.

Beaker and Erlenmeyer flask have a greater diameter and their grauation is every 10.0 mL. So, their error % is larger.

Answer:

The answer would be 100 ml graduated cylinder

Explanation:

The energy speed!!!!

Answer:

the rigid outer part of the earth, made up of the crust and upper mantle.

Explanation:

Google’s definition

A lithosphere is the rigid, outermost shell of a terrestrial-type planet, or natural satellite, that is defined by its rigid mechanical properties. On Earth, it is composed of the crust and the portion of the upper mantle that behaves elastically on time scales of thousands of years or greater.

Answer:

NH₄⁺

H₂PO₄⁻

H₃O⁺

Explanation:

So, the species that are ions are:

NH₄⁺

H₂PO₄⁻

H₃O⁺

Answer:

NH₄⁺

H₂PO₄⁻

H₃O⁺

Explanation:

Final answer:

The bond between calcium (Ca) and bromine (Br) is an ionic bond, where calcium donates electrons to form Ca2+ ions, and bromine atoms each gain an electron to form Br- ions, creating an ionic compound.

Explanation:

The bond between calcium (Ca) and bromine (Br) in the compound CaBr2 is an ionic bond. This type of bond is formed when one atom (in this case, calcium) donates one or more electrons to another atom (in this case, bromine).

Calcium is a metal with a tendency to lose electrons and form a positive ion (Ca2+), while bromine is a non-metal with a tendency to gain electrons and form a negative ion (Br−).

When calcium gives up two electrons, one for each bromine atom, each bromine atom gains one electron, resulting in two Br− ions. These oppositely charged ions attract each other, creating an ionic bond.

With a process called Fission. This generates heat to produce steam.

Answer:

True.

Explanation:

the answer to your question is True !

Answer:

[tex]\boxed{\text{(a) 0.001 66 mol MOH; (b) 200 g/mol}}[/tex]

Explanation:

I am assuming that the unknown acid is monobasic. Then the general equation for the reaction is

HA + MOH ⟶ MA + H₂O

(a) Moles of MOH

[tex]\text{Moles of MOH}= \text{0.008 72 L MOH} \times \dfrac{\text{0.19 mol MOH}}{\text{1 L MOH}} = \text{0.001 66 mol MOH}[/tex]

(b) Moles of HA

Now, you use the molar ratio from the balanced chemical equation to find the moles of unknown acid.

[tex]\text{Moles of HA = 0.001 66 mol MOH} \times \dfrac {\text{1 mol HA}}{\text{1 mol MOH }} = \text{0.001 66 mol HA}[/tex]

(c) Molar mass of HA

[tex]\text{MM} =\dfrac{\text{mass}}{\text{moles}}= \dfrac{\text{0.33 g}}{\text{0.001 66 mol}} = \text{200 g/mol}[/tex]

The molar mass of the unknown acid is [tex]\boxed{\textbf{200 g/mol}}[/tex]

Final answer:

The percent composition of iron in FeCl3 is 34.43%.

Explanation:

The percent composition of iron in FeCl3 can be calculated by dividing the mass of iron by the molar mass of FeCl3 and multiplying by 100%. FeCl3 consists of one iron atom and three chlorine atoms. The atomic mass of iron is 55.845 g/mol and the atomic mass of chlorine is 35.453 g/mol. Therefore, the molar mass of FeCl3 is 55.845 g/mol + 3 * 35.453 g/mol = 162.204 g/mol. The mass of iron in FeCl3 is 55.845 g/mol / 162.204 g/mol * 100% = 34.43%.

Answer:

215.6 g.

Explanation:

no. of moles (n) = mass/molar mass.

∴ mass of C₃H₄O₃ = (no. of moles)*(molar mass) = (2.45 mol)(88.0 g/mol) = 215.6 g.

Answer: A. A photon was released.

An electron moved from a higher energy level to a lower energy level. What most likely happened during the transition? (5 points)

A. A photon was released.

B. A photon was absorbed.

C. A fixed amount of energy was absorbed.

D.  A random amount of energy was released.

Explanation:

I just took the test and A. A photon was released is the correct answer!

Good Luck!!

( P.S.- I just used the other answer on the test and it was incorrect, but this one is correct because I finished the test and got the answer key!)

During the electron's transition from a higher to a lower energy level, it most likely released energy, possibly in the form of light, consistent with Bohr's model of the atom.

When an electron moves from a higher energy level to a lower energy level, it most likely emitted energy. This concept is grounded in Bohr's model of the atom where each electron orbit is an energy level with a specific energy value. A transition between these levels involves a change in the electron's energy, corresponding to the energy difference between the levels.

For example, if an electron moves from level 8 to level 1, it descends through several energy levels and, according to Bohr's model, emits energy at each transition. This energy can be quantified, such as in the change of -10.2 eV from a higher to a lower state, releasing 10.2 eV of energy. The emitted energy often manifests as light, with the color depending on the energy change involved.

Answer:

Ammeter

Explanation:

An ammeter (from Ampere Meter) is a measuring instrument used to measure the current in a circuit. Electric currents are measured in amperes (A), hence the name. Instruments used to measure smaller currents, in the milliampere or microampere range, are designated as milliammeters or microammeters.

An endothermic reaction occurs when the energy used to break the bonds in the reactants is greater than the energy given out when bonds are formed in the products. This means that overall the reaction takes in energy, therefore there is a temperature decrease in the surroundings.

Answer:

There is a temperature decrease in the surroundings

Explanation:

An endothermic reaction occurs when the energy used to break the bonds in the reactants is greater than the energy given out when bonds are formed in the products. This means that overall the reaction takes in energy, therefore there is a temperature decrease in the surroundings

Metallic element in list of paper is Titan.

Answer:

N₂ + 3H₂ → 2NH₃. "synthesis reaction".

Explanation:

To balance the equation, you should apply the law of conservation of mass for the equations.

The law of conservation of mass states that the no. of each atom is equal in both sides (reactants and products).

The balanced equation is:

N₂ + 3H₂ → 2NH₃.

It is a synthesis reaction that 2 reactants give 1 product.

That 1.0 mole of N₂ reacts with 3.0 moles of H₂ to produce 2.0 moles of NH₃.

The no. of all atoms is the same in both of reactants and products side.

N (2), and H (6).

The equivalent weight is the gram molecular weight divided by the number of electrons lost or gained by each molecule; For sodium thiosulfate (Na2S2O3·5H2O), this is (248.17/1) g.

The extensive properties come under physical property which depends on the size of the system. The enthalpy comes under extensive property which is a thermodynamic property where the internal energy; and the pressure and volume of the system is related.

The change in enthalpy is related to energy transfer at certain pressure which is related to the endothermic and exothermic reactions taking place on the system. Since, all these reactions and heat transfer from the system to the environment is based on the physical property, enthalpy is called as extensive property.

Answer:

155 kJ of energy will be released.

Explanation:

The [tex]\rm \Delta H\textdegree[/tex] ([tex]\rm \Delta H \textdegree_\text{rxn}[/tex] in some textbooks) here stands for standard enthalpy change per mole reaction. To find the amount of energy released in this reaction, start by finding the number of moles of this reaction that will take place.

How many moles of atoms in 4.72 grams of carbon?

Relative atomic mass data from a modern periodic table:

[tex]\displaystyle n = \frac{m}{M} = \rm \frac{4.72\;g}{12.01\; g\cdot mol^{-1}} = 0.393006\; mol[/tex].

The coefficient of carbon in the equation is one. In other words, each mole of the reaction will consume one mole of carbon. Oxygen is in excess. As a result, [tex]\rm 0.393006\; mol[/tex] of carbon will support [tex]\rm 0.393006\; mol[/tex] of the reaction.

How much energy will be released?

The [tex]\rm \Delta H\textdegree{}[/tex] value here is negative. But don't panic. [tex]\rm \Delta H\textdegree{}[/tex] is the same as the chemical potential energy of the reactants minus the products in one mole of the reaction. [tex]\rm \Delta H\textdegree{} = -393.5\;kJ[/tex] means that the chemical potential energy drops by [tex]\rm 393.5\; kJ[/tex] during each mole of the reaction (with the coefficients as-is.) Those energy difference will be released as heat. In other words, one mole of the reaction will release [tex]\rm 393.5\;kJ[/tex] of energy.

The 4.72 grams of carbon will support [tex]\rm 0.393006\; mol[/tex] of this reaction. How much heat will that [tex]\rm 0.393006\; mol[/tex] of reaction release?

[tex]Q = n \cdot (-\Delta \text{H}\textdegree{}) = \rm 0.393006\times 393.5 = 155\;kJ[/tex].

As a side note, the mass of carbon 4.72 grams is the least significant data in this question. There are three significant figures in this value. As a result, keep more than three significant figures in calculations but round the final result to three significant figures.

The energy released when 4.72g of carbon reacts with excess oxygen to form CO₂ is -154.8 kJ.

To determine how many kJ of energy are released when 4.72g of carbon reacts with excess oxygen to produce carbon dioxide, we use the given enthalpy change (ΔH) for the reaction:

First, we need to find the number of moles of carbon in 4.72g:

Molar mass of carbon = 12 g/mol

Moles of carbon = mass / molar mass = 4.72 g / 12 g/mol = 0.3933 mol

The reaction for the combustion of carbon to form CO₂ is exothermic, with ΔH = -393.5 kJ/mol.

The total energy released is calculated as follows:

Energy released = moles of carbon x ΔH
Energy released = 0.3933 mol x -393.5 kJ/mol = -154.8 kJ

Thus, the energy released when 4.72g of carbon reacts with excess oxygen is -154.8 kJ.

Answer: Water

Explanation: Water is an example of transparent because light can pass through it. Air is also an example.

Final answer:

A transparent object, such as a clean glass window, transmits light without significant absorption or reflection. The quality that makes an object transparent is its ability to let light pass through it effectively, as seen in high-quality diamonds, which refract white light and disperse it into its composite colors, causing a sparkling effect.

Explanation:

An object that is transparent allows light to pass through it without scattering, making it possible to see through the object clearly. A common everyday example of a transparent object is a clean glass window. Glass is transparent because it transmits light rather than absorbing or reflecting it, thus allowing a high proportion of the light spectrum to pass through without significant distortion.

The quality that makes an object transparent is its ability to transmit light waves effectively. When light encounters a transparent material, the photons that make up the light are not significantly absorbed by the material's atoms or reflected away, but rather they pass through the atomic structure of the material without being scattered.

A perfect example of this phenomenon is a high-quality diamond, which is clear and colorless, transmitting all visible wavelengths of light. The diamond sparkles with flashes of brilliant color when illuminated by white light because it refracts, or bends, the light, splitting it into its composite colors in a process similar to a prism. This is known as dispersion, which coupled with the internal reflections within the diamond due to its cut and high refractive index, causes the sparkle with various colors.

Answer:

Explanation:

                  Fe + Cl₂ →  FeCl₃

a. The balanced equation

    All chemical equations obey the law of conservation of matter. To balance this above equation, we either inspect or use mathematical method to obtain a balanced equation.

We put coefficients a, b and c at the back of the compounds as shown below:

                    aFe + bCl₂ →  cFeCl₃

For Fe:

      a = c                          (i)

For Cl:

     2b = 3c                        (ii)

let a = 1, c= 1

Solving for the unknown b, we have:

          b = [tex]\frac{3c}{2}[/tex]

           b = [tex]\frac{3}{2}[/tex]

The complete reaction equation is therefore:

            Fe + [tex]\frac{3}{2}[/tex]Cl₂ →  FeCl₃

                                     or

                       2Fe + 3Cl₂ →  2FeCl₃

Problem a:

Mass of reacting iron = 25g

unknown: number of moles of iron

Solution

To find the number of moles, we apply the mole concept using the expression below:

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

To find the molar mass of the reactant iron, we know atomic mass of iron is 56g.

The molar mass is therefore, 56gmol⁻¹

[tex]number of moles = \frac{25}{56} \\[/tex]

number of moles of the iron reactant  = 0.45mole

Problem b:

From the balanced equation of the reaction:

             2Fe + 3Cl₂ →  2FeCl₃

      2 moles of Fe produces 2 moles of FeCl₃

     So 0.45mole of Fe would produce 0.45 mole of FeCl₃

Problem C:

Applying the mole concept;

      mass of FeCl₃ = number of moles of FeCl₃ x molar mass of FeCl₃

     number of moles of FeCl₃ = 0.45mole

     molar mass of FeCl₃ = ?

Atomic mass of Fe = 56g

                          Cl = 35.5g

      Molar mass of FeCl₃ = 56 + (3 x 35.5) = 56 + 106.5 = 162.5gmol⁻¹

mass of FeCl₃ = 0.45 x 162.5 = 73.1g