Select one or more correct answers.
Hakeem is testing the effects of sunlight on samples of soil. Which of these actions would introduce confounding variables into Hakeem’s experiment?

A. He tests a theory that’s already been established.
B. He tests multiple hypotheses at a time.
C. He uses identical specimens when completing multiple trials.
D. He adjusts the independent variable and records the effects.
E. He uses different types of soil in each of his samples.

Answers

Answer 1

He tests multiple hypotheses at a time and He uses identical specimens when completing multiple trials.

The two options are correct B,C.

Which four sorts of experiments are there?

While experimentation as a whole encompasses this form of research, individual research designs have certain characteristics. The four main design types that are pertinent to user experience design are appropriate in this study, scientific, and developed a semi.

A true experiment is what?

Any randomized experiment may occasionally be referred to as a real experiment. In other cases, the phrase "true experiment" is used to refer to any investigations that have at at one continuous dependent variable and at least one free variables that is experimentally changed. When experiments are also used to determine whether a theory-based idea, axiom, or phenomenon is true, they play a crucial role in the evolution of science.

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Related Questions

What is the mRNA sequence that will be formed from the DNA sequence below?
TAC CGG ATG CCA GAT CAA ATC

Answers

It will form the following: mRNA sequence will be 3' AUG CCA GGG UCG AAU UUC GAA UAG GCC CA 5'.

What is mRNA sequence?

High-throughput sequencing methods are used in RNA sequencing (RNA-Seq) to reveal the transcriptome of a cell. Compared to prior Sanger sequencing- and microarray-based techniques, RNA-Seq provides far greater coverage and better resolution of the dynamic dynamics of the transcriptome. In addition to allowing for the quantification of gene expression, RNA-Seq data also allows for the identification of novel transcripts, the recognition of alternatively spliced genes, and the detection of allele-specific expression.

Recent advancements in the RNA-Seq approach, which entails sample preparation, library building, and data analysis, have allowed researchers to better comprehend the functional complexity of the transcription. In addition to polyadenylated messenger RNA (mRNA) transcripts, total RNA, pre-mRNA, and noncoding RNA, including microRNA and long ncRNA, can all be explored using RNA-Seq.

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when a solution of cesium chloride (cscl) is subjected to high-speed centrifugation, a stable density gradient is formed. meselson and stahl found that when cell contents were subjected to centrifugation with a cscl solution, a band of dna formed at the cscl density that matched the density of the dna. this technique is called density-gradient centrifugation. the test tubes below show the results of density-gradient centrifugation of five different dna samples. drag the description of each dna sample to the appropriate location to identify the expected appearance of the dna band(s) after density-gradient centrifugation.

Answers

Test Tube 1: DNA from E. coli cells grown in 14N

Test Tube 2: DNA containing one strand of 15N-DNA and one strand of 14N-DNA

Test Tube 3: DNA from E. coli cells grown in 15N

Test Tube 4: A 1:1 mixture of DNA from cells grown in 14N and cells grown in 15N

Test Tube 5: A 1:1 mixture of DNA from cells grown in 14N and 15N, heated (to disrupt hydrogen bonds) and cooled (to allow reannealing)

Meselson and Strahl had used CsCl gradient centrifugation to demonstrate the semi-conservative nature of DNA replication. In a CsCl density gradient centrifugation, from a pool of light heavy and intermediate-size DNA, the heaviest one would go and settle towards the bottom of the test tube.

While the lightest one would be at the top and the intermediate one would find a place in between the heavy and the lighter one. If the DNA is labeled only with 15N then the DNA is heavier in size and the DNA would settle towards the bottom of the tube during density gradient centrifugation.

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In one to two sentences, explain a similarity and a difference between the particles in liquid water at 100°C and the particles in
steam at 100°C. (2 points)

Answers

A similarity between the particles in liquid water and the particles in steam is their chemical composition whereas a difference between the particles in liquid water and the particles in steam is their state of matter.

What are liquid and steam?

Steam refers to the gas which is formed when water passes from the state of liquid to the gaseous state. Steam is formed when water molecules break the bonds i.e. hydrogen bonds that keep them together while on the other hand, a liquid is a sample of matter that takes the shape of a container in which it is placed. The term liquid is used to show the state or condition of matter.

So we can conclude that chemical composition is the similarity between liquid and steam while on the other hand, the difference in the state of matter.

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when solutions of silver perchlorate, agclo4(aq) , and ammonium iodide, nh4i(aq) , are mixed, a solid precipitate forms, indicating a reaction.

Answers

The products are AgI and NH4ClO4.

Moreover, Iodide of Pb2+, Ag+ and Hg22+ are insoluble. So, AgI is not soluble Ammonium Salts are soluble. So, NH4ClO4 is soluble.

AgClO4(aq) + NH4I(aq) -> AgI(s) + NH4ClO4(aq)

Ag+(aq) + I-(aq) -> AgI(s)

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What is the formula of the compound formed between chlorine (Cl) and calcium (Ca)?


A. CaCl, because calcium loses one electron and chlorine gains one electron.
B. ClCa, because chlorine gains one electron and calcium loses one electron.
C. CaCl2, because calcium loses two electrons and chlorine gains one electron.
D. ClCa2, because chlorine gains one electron and calcium loses two electrons.

Answers

Answer:

C.

Explanation:

From the periodic table: Cl has a -1 charge while Ca has a +2

This means that 2 Cl required to make a neutral compound with Ca (ideal)

If you forgot to add the primers to your pcr reaction, what would happen and why?.

Answers

If you forget to add primers to your PCR reaction, the reaction will not work because the primers are necessary for the DNA amplification process.

What are primers?

A primer is a brief sequence of nucleic acids that serve as the precursor to DNA synthesis. Short RNA strands make up primers in living things. Prior to DNA replication, an enzyme called primase, a subtype of RNA polymerase must create a primer.

Because Taq polymerase cannot add bases without an existing piece of DNA, your PCR reaction would fail if you forgot to add the primers. Because there wouldn't be an enzyme that could add additional nucleotide bases, your reaction would not succeed.

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how are hydrogens removed from polyprotic acids? how does this relate to the ka of these same species?

Answers

A lot of acids have two or more ionizable hydrogens. In phosphoric acid H3PO4, there are three, and there are two in carbonic acid H2CO3.

what is a polyprotic acid?

A substance that can contribute more than one proton is called polyprotic acid. Two different types of polyprotic acid—diprotic and triprotic—can each donate two or three protons.

Polyprotic acids have different dissociation constants, such as Ka1, Ka2, Ka3, and equivalence points, depending on how frequently dissociation occurs.

Polyprotic acid example

Take sulfuric acid as an example of a diprotic polyprotic acid (H2SO4). The sequential deprotonation of sulfuric acid (H2SO4) results in the production of HSO4- and SO42-, respectively.

Take sulfuric acid as an example of a diprotic polyprotic acid (H2SO3). To create HSO3-, sulfuric acid (H2SO3) is sequentially deprotonated.

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according to orwell, what does president truman say about the atomic bomb?

Answers

According to Orwell president Truman says that the bomb is incredibly expensive, and only three or four countries in the world are able to produce it due to the massive industrial effort required.

Truman said that the only factor in his decision to drop the bomb was the military. It is believed that a Normandy-style amphibious landing would have resulted in one million fatalities. Truman thought the bombs also helped save Japanese lives. The President had no intention of extending the conflict. American lives had already been lost as a result of more than 3,500 Japanese kamikaze raids. But he didn't anticipated the effect of bomb on human's.

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calculate the amount of heat needed to melt of solid acetic acid () and bring it to a temperature of . be sure your answer has a unit symbol and the correct number of significant digits

Answers

The amount of heat needed to melt of solid acetic acid is 32.4 kJ.

Given temperatures are

Heat capacity for acetic acid = 2.06 J/g* °C

The melting point of acetic acid = 16.64 °C

Enthalpy of fusion for acetic acid = 11.73 kJ/mol

Number of moles of acetic acid = 124 g/(60.05 g/mol) = 2.064946 mol

1. Conversion of solid acetic acid at 16.64 °C to liquid acetic acid at 16.64 °C

q1 =m*ΔHf = 2.064946 mol * 11.73 kJ/mol = 24.22182 kJ

2. Conversion of liquid acetic acid at 16.64 °C to gas at 48.7 °C

q2 = m*C*ΔT = 124 g* 2.06 J/g* °C * (48.7 – 16.64 ) °C = 8189.406 J = 8.189406 kJ

Total heat energy required = q1 + q2

= 24.22182 + 8.189406 = 32.41122 kJ

The heat energy required = 32.4 kJ.

The inlet temperature to the heat exchanger at B will be T1. And the output of the heat exchanger coming out at D is T2. The cooling water entering the heat exchanger heats up as it passes through the heat exchanger. q is the amount of heat transferred to the system used to represent the change in enthalpy. Enthalpy is the total potential energy of a system associated with heat transferred to and from the system.

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determine the shape around each central atom in the acetate ion. draw the lewis structure first. (enter one of the following: linear, trigonal planar, tetrahedral, trigonal pyramidal, bent, trigonal bipyramidal, seesaw, t-shaped, octahedral, square pyramidal, square planar) 1. carbon 1 2. carbon 2 (the one with the oxygens)

Answers

We must first draw the Lewis structure of acetic acid.

(figure attached)

Carbon 1

This atom has four atoms directly attached and no lone pairs.

Its electron geometry and its molecular geometry are both tetrahedral as in methane. (figure attached)

Carbon 2

This atom has three atoms directly attached and no lone pairs.

Its electron geometry and its molecular geometry are both trigonal planar.

Oxygen 3

This atom has two atoms directly attached and two lone pairs.

Its electron geometry is tetrahedral but its molecular geometry is bent as in water. (figure attached)

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Naming and Writing Formulas Assignment.

Answers

Answer:

Having difficulties !!! screen shotted it :)

16. H20 - Covalent

17. Mn(NO2)2 - Ionic and called Manganese(II) nitrate

18. HgO - Ionic

19. Li3N - Covalent

Atomic radius generally decreases from left to right across a period because the effective nuclear charge _____ while electrons are being added to the same outer level. These additional electrons are shielded _____ by inner electrons and are therefore attracted _____ strongly by the nucleus.

Answers

Atomic radius generally decreases from left to right across a period because the effective nuclear charge Increases while electrons are being added to the same outer level. These additional electrons are shielded less well by inner electrons and are therefore attracted more strongly by the nucleus. .

In the periodic table, atomic radii generally decrease as you move left to right across the period (because the nuclear charge increases) and increase as you move down the group (because the number of electron shells increases).

As the attractive force between the nucleus and the electron increases, the size of the atom decreases. This effect diminishes as you move further to the right within the cycle. This is due to repulsion between electrons that would otherwise cause the atoms to increase in size.

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Give the IUPAC name for the following polyfunctional compound: OH 6-ethyl-5-methyl-7-octen-4-ol

Answers

The IUPAC name of the polyfunctional compound OH 6 -ethyl-5-methyl-7-octen-4-ol is 5-ethyl-6-methyloct-7-en-4-ol.

The given compound is OH 6-ethyl-5-methyl-7-octen-4-ol

 According to the IUPAC rule,

The longest chain is first taken which is called the parent chain.Numbering starts from the C-atom in the parent chain according to the highest priority group or atom attached to that carbon.

In the given molecule, OH-group is the highest priority group and therefore, numbering starts from the C-atom where OH-attached to the least C-atom number.

The given compound contains 8 C-atom in the longest C-chain in which the hydroxyl group (OH) is attached to the 4th C-atom and alkene functional group is attached to 8th position of the parent chain. The ethyl substituent is attached to the 5th C-atom while methyl substituent is attached to the 6th C-atom of the parent chain.

Substituent are named alphabetically , according to IUPAC rule.

Therefore, the IUPAC name of the given compound is 5-ethyl-6-methyloct-7-en-4-ol.

What does IUPAC mean?

IUPAC is an abbreviation for Global Association of Unadulterated and Applied Science. The IUPAC is the perceived expert for synthetic guidelines of terminology, estimations, and nuclear mass qualities, setting the norms of nuclear loads that show up on the periodic table.

Also Known As: International Union of Pure and Applied Chemistry.

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The bond strength for the diiodine bond – the bond in the i_2 molecule – is 149 kj/mol. What is the longest wavelength of light, in nm, that will break the diiodine bond?.

Answers

The longest wavelength of light that will break the diiodine bond is 803 nm.

What is bond strength?

In chemistry, the strength with which a chemical bond keeps two atoms together is known as bond strength. This is typically represented in terms of the energy needed in kilocalories per mole to break the bond.

The terms bond-dissociation energy and bond-dissociation enthalpy, which are sometimes used interchangeably, are related concepts. However, some publications distinguish between the bond-dissociation energy (D0) and the bond-dissociation enthalpy, which is used to describe the enthalpy change at 298 K (clearly indicated DH°298). In theoretical and computational study, the former value is frequently preferred, although the latter is more practical for thermochemical studies. The numerical difference between the quantities in normal chemical systems is negligible, therefore it is sometimes possible to ignore the distinction. The equation D0(RH) DH°298(RH) 1.5 kcal/mol is a fair approximation for a hydrocarbon RH, where R is much bigger than H, for example.

wavelength(λ ) = h c/ E

where h= Plank's constant

           c = velocity of light

           E = Energy ( here it is bond strength)

  Energy required to break one double bond of Iodine (E) =  149× 1000 /(6.02214076 × 10^23) = 2.474 * 10 ^ -19 J

  λ  = (6.62607015 × 10^-34 m2 kg / s × 3 × 10^8 m/s) /  (2.474 * 10 ^ -19 J)

           λ =8.03484658 × 10^ -7

            λ = 803× 10^ -9 m

             λ = 803 nm

Hence, the longest wavelength of light that will break the diiodine bond is 803 nm.

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Identify the part of the atom that most determines the chemical properties of the atom.

Answers

The number of protons in the nucleus that determines the chemical properties of an atom.

What is proton ?

A proton is a stable subatomic particle with the symbol p, H+ or 1H+ and a positive charge of +1 e elementary charge. Its mass is slightly less than that of a neutron, 1836 times that of an electron (proton-to-electron mass ratio). Protons and neutrons, each with about one atomic mass unit, are collectively called "nucleons" (particles present in the nucleus).

All atoms have one or more protons in their nucleus. They ensure an electrostatic central force of attraction that binds atomic electrons together. The number of protons in the nucleus is the defining property of an element and is called the atomic number (denoted by the symbol Z). Since each element has a unique number of protons, each element has a unique atomic number, which determines the number of atomic electrons and, consequently, the chemical properties of the element.

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1. What do you notice as the rock
changes over time?
2. What do you notice about the fossils
over time?

Answers

Answer: the rock changes color because of the temputure and stays the same because its still a rock...

Explanation:

someone please help with number 14 letters a-d i don’t understand it!!

Answers

MgCO3⇒ MgO+CO2 is the balance equation reaction.

a. Li+O2⇒ LiO2

b. H2+Cl2⇒ H2Cl2

c.MgCO3⇒ MgO+CO2

d.2NaI+Cl2⇒ 2NaCl+2I

To balance chemical equations, stoichiometric coefficients for the reactants and products are required. This is important because a chemical equation must follow the rules of conservation of mass and constant proportions, which dictate that the same number of atoms of each element must be avail on two of the reactant and product sides of the equation.

Chemical equations use the relevant chemical formulae to symbolically express the reactants and products of a chemical process. To the left of the sign "," and to the right of the arrow symbol, respectively, is the part of the chemical equation that is on the reactant side.

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Determine whether each alcohol could be a major product of the acid-catalyzed hydration of an alkene.

Answers

Water is added to an alkene during an acid-catalyzed hydration reaction to create alcohol: A sequential mechanism for the reaction begins with the protonation of the double bond.

How does the hydration of alkenes by acid work to produce alcohols?

Alcohol is produced when alkenes are hydrated with acid in accordance with Markownikoff's rule. Alkenes can also be converted into alcohols by the processes of hydroboration oxidation and oxy-mercuration-de-mercuration.

Water adds to alkenes only in the presence of an acid catalyst, resulting in the production of alcohol. However, there are two significant drawbacks to the acid-catalyzed hydration: Arrangements may change. Regioselectivity is unpredictable.

Hydration is the process of adding water to alkenes on a net basis. The pi bond in the alkene and the OH bond in the water are broken as a result, and a C-H bond and a C-OH bond are formed. Typically, the reaction is exothermic by 10 to 15 kcal/mol1, although the entropy change is between -35 and -40.

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The atomic number of potassium is 19. How does the isotope potassium 39 differ from isotope potassium 41?.

Answers

To learn isotope and atomic number.

What is isotope?

Atoms that contain variable numbers of neutrons but the same number of protons are called isotopes. Despite having almost equal chemical properties, they have different masses, which affects their physical characteristics.

What is atomic number?

The number assigned to a chemical element according to its atomic number in the periodic system, which places the elements in ascending order of the number of protons in their nuclei. As a result, the atomic number is also determined by the number of protons in the neutral atom, which is always equal to the number of electrons.

Since the number of protons in each of these isotopes is the same, potassium-39 has one fewer neutron than potassium-40 and two fewer than potassium-41. In a similar vein, potassium 40 has one fewer neutron than potassium 41.

Therefore,  potassium 40 has one fewer neutron than potassium 41.

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An organic compound x containing 40% carbon 6.67% hydrogen the rest being oxygen. If x has a relative molecular mass of 60 determine its
Empirical formula
Molecular formula (A=1;C=12,0=16)

Answers

The empirical formula of the compound is  [tex]CH_{2} O[/tex] while the molecular formula is [tex]C_{2}H_{4} O_{2}[/tex]

What is the Empirical formula?

There are several formulas that a compound can have and these formulas that a compound can have include;

a) Molecular formula

b) Empirical formula

c) Structural formula

The empirical formula is the simplest formula that a compound can have. This formula shows the ratio of the toms that are found in the compound has we can see it. Let us now obtain the empirical formula.

Dividing each term by the relative atomic mass we have;

Percentage of oxygen = (100 - (6.67 + 40)) = 53.33%

C -  40/12    H - 6.67/1     O - 53.33/16

Dividing through by the lowest ratio;

C - 3.33/3.33     H - 6.67/3.33        O - 3.33/3.33

C - 1                   H - 2                       O - 1

The empirical formula is [tex]CH_{2} O[/tex]

The molecular formula is obtained from;

[12 + 2 + 16]n = 60

n =2

The molecular formula is;

[tex]C_{2}H_{4} O_{2}[/tex]

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Why is taq dna polymerase used in pcr reactions rather than a normal dna polymerase?.

Answers

Taq polymerase can withstand the high temperatures involved in PCR reactions.

How does DNA replication use polymerase?

A DNA polymerase belongs to a group of enzymes that catalyzing the synthesis of Target dna from nucleoside triphosphates, which are the basic building blocks of DNA. These enzymes, which are necessary for DNA replication, typically function in groups to split a single dna Template duplex into two identical DNA duplexes.

In plain English, what is polymerase?

Definition. All living things have DNA polymerase, a particular sort of enzyme. DNA replication and DNA repair and maintenance are its two main goals. The enzyme is essential for passing on genetic information from one generation to the next.

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a substance is dissolved in water, forming a 0.50m solution. if 8.0 liters of the solution contains 240 grams of the substance, what is the molecular mass of the substance?

Answers

When a substance is dissolved in water, forming a 0.50m solution and  8.0 liters of the solution contains 240 grams of the substance then the molecular mass of the substance is 60 g/mol.

Given,

m = 240 g

MM = 0.5 mol/L

V = 8 L

∴ M = m/(MM × V)

⇒ MM = m/(M × V)

Where,

m = mass

M = number of moles

V = volume in L

MM = molecular mass

Substituting the values we get,

Molecular mass = 240 g/(0.5 mol L⁻¹ × 8 L)

⇒Molecular mass = 240/4 g/mol = 60 g/mol

Hence, the molecular mass of the substance is 60 g/mol.

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Arrange the following from lowest to highest entropy: H,0(), H,O2(0 H20(g), CuO(s). Assume 1 mole of each at the same conditions. from lowest to highest entropy Drag and drop your selection from the following list to complete the answer: H20(e) H20(g) CuO(s) H202(e)

Answers

Arrangement from lowest to highest entropy will be CuO (s) < H₂O (l) < H₂O₂ (l) < H₂O (g)

The dispersed energy of any system is called the entropy of the system. In simple words, this energy cannot be used to perform any activity. As we know that the highest degree of randomness is present in gasses because gas molecules move in the system in a random manner. The degree of randomness is slightly lower in liquids than in gasses because liquid molecules have different forces like hydrogen bonding dipole forces etc. These forces maintain the degree of randomness. In solid substances, the molecules remain in a fixed position so the degree of randomness is almost zero.

So among the given molecules, H₂O has the highest entropy and CuO has the lowest. if Two molecules have the same phase then we will decide according to the molecular formula.

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mse 2001 which of these monomers could be used for a free radical, chain growth polymerization? (choose all that could be used)

Answers

Mse 2001 which of these monomers could be used for a free radical, chain growth polymerization have reactive carbon carbon double bond

The monomers like alkenes or dienes undergo polymerization in the presence of free radicles and benzoyl peroxide form a free radicle and thereby it act as initiator for free radicle chain growth polymerization and it used one of the pi bond electron to form a stable bond with another carbon atom and other electron return to the second carbon atom and turning the whole molecule into radicle and after initiation the chain propagates until no monomer is left or termination start

Only monomers having anion stabilizing substituent such as phenyl cyano or carbonyl are good substrate for this polymerization technique

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a 25.0 ml sample of a saturated ca(oh)2 solution is titrated with 0.030 m hcl, and the equivalence point is reached after 38.1 ml of titrant are dispensed. based on this data, what is the concentration (m) of ca(oh)2? type answer:

Answers

When samples ca(oh)2 is titrated with HCL, then the concentration of ca(oh)2 is calculated as 0.09M.

What is neutralization reaction?

In chemistry, neutralization is a chemical reaction in which acid and base react with each other.  During reaction in water, neutralization results in no excess of hydrogen or hydroxide ions present in the solution.

The neutralization of acid and base to identify the strength can be given as:

M1V1= M2V2

Substituting the strength and the volume of calcium hydroxide and the HCl with the volume:

0.030 * 38.1 =  M2 * 25

M2 = 1.143/25

=0.045 M

The strength of the calcium hydroxide in the reaction is 0.045 M.

One molar unit of calcium hydroxide gives 2 molar units of hydroxide;

Therefore, molar unit of hydroxide in 0.045 M calcium hydroxide is:

2 * 0.045 = 0.09 M

The concentration of hydroxide ion in the titration is  0.09M.

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you weigh out an antacid tablet and determine the mass to be 1.1990 g. after taking a 0.2455 g sample of the antacid tablet, you dissolve it in 25.00 ml of a 0.1006 m solution of hydrochloric acid in a 250.0 ml erlenmeyer flask. after heating the solution to get rid of carbon dioxide, you titrate the leftover hydrochloric acid in the solution in the erlenmeyer flask with a 0.09913 m solution of sodium hydroxide and determine that it takes 14.71 ml of the sodium hydroxide solution to react with the leftover hydrochloric acid in solution. determine the milligrams of calcium carbonate in the sample of antacid tablet and then determine the milligrams of calcium carbonate in the entire antacid tablet. 2. what indicator will be used for this titration reaction? what color change will occur?

Answers

Convert moles of  HCl used in the neutralization of the tablet to moles of CaCO3 using the coefficients in the balanced equation. That will be moles of CaCO3 is 0.0005284 moles.

1. CaCO3 + 2HCl ==> CaCl2 + H2O + CO2

Moles of HCl added initially = M x L = 0.002515  moles

Moles of NaOH needed to neutralize the excess HCl = M x L = 0.0014582 moles.

Moles of HCl used for the tablet is

0.002515 - 0.0014582 =  0.0010568 moles

Convert moles of  HCl used in the neutralization of the tablet to moles of CaCO3 using the coefficients in the balanced equation. That will be moles of CaCO3 = (1/2 x moles HCl) = 0.0005284 moles

Mass of CaCO3 = 0.05284g in 1.1990 g tablet

Then in 0.2455 g tablet = 0.0065187 g = 6.5187 mg

2. Both HCl and NaOH are strong acid and  strong bases respectively, an indicator like phenolphthalein is used which can  become colourless in acidic and neutral conditions and pink coloured under alkaline conditions.

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block
wood with blac
4. Find the density of a piece of wood with a mass of 50.0 grams and a volume of 100. cm³.
=2g/cm3
Will it float on water?

Answers

It float on water density= 2.27 g/ml.

What is density?

density is the mass of a material substance per unit volume. d = M/V, where d is density, M seems to be mass, and V is volume, is the formula for density. Grams per cubic centimetre are a common unit of measurement for density. For instance, while Earth has a density of 5.51 grammes per cubic centimetre, water has a density of 1 grammes per cubic centimetre. The unit of density is kilogrammes per cubic metre. For instance, air weighs 1.2 kilogrammes per cubic metre. In textbooks and manuals, the densities of typical solids, liquids, as well as gases are listed.

Density is considered an important factor in identifying a substance. Some examples of highly dense materials are iron and platinum.

As per the question

Density = mass /volume

The mass peice of sulphur= 227gm

Displaed in 50 ml of water .

Thus,

Density= 227 g/ (150-50) mL

= 2.27 g m/L

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Which trends increase moving across a row on the periodic table? select all that apply.

Answers

The increased trends moving across a row on the periodic table is: the atomic radius generally decreases as we move from left to right. This is affected by the number of electrons each atom contains.

What are the trends in a row of the periodic table?

Moving from left to right at the same row, the atomic radius generally decreases. This is because the more to the left, the more electrons each atom has. As they have the same number of shells, the atoms in the further right of the table tend to have a smaller atomic radius.

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If 2.15 moles of C₂H4 (ethane) reacts with 6.30 moles of O2, which is the
limiting reagent?

Answers

Answer:

Oxygen is the limiting reagent.

Explanation:

First you must make a chemical equation. Then you will do a mole bridge from the moles of each given substance to a product, you can find how much product each will create. The reactant that creates the least is the limiting reagent. I hope this helps!

Silver tarnishes as silver metal reacts with hydrogen sulfide, h2s, in the air. in this reaction, dark silver sulfide, au2s, covers the surface of silver. when silver is polished, this coating of silver sulfide can be removed from the surface. this makes the silver shiny again. enter the coefficients that balance the tarnishing reaction equation. (type 1 for no coefficient.) 2 silver dishes. photo by mgeurts ag(s) h2s(g) → ag2s(s) h2(g)

Answers

To make the silver shiny again, we can do silver tarnishes. The balanced tarnishing reaction is 2Ag(s) + H2S(g) --> Ag2S(s) + H2(g). Hence, the correct coefficients for the reaction above are: 2, 1, 1, 1.

How to write a balanced chemical equation?

A balanced reaction is when the coefficient of all atoms in the reactants (the left side) is the same as the products (the right side). Given this equation:

Ag(s) + H2S(g) --> Ag2S(s) + H2(g)

The balanced reaction is:

2Ag(s) + H2S(g) --> Ag2S(s) + H2(g)

Hence, the coefficients of the reaction above are: 2, 1, 1, and 1.

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