Determining nitrogen balance in the clinical setting can be very valuable. To determine a client’s state of nitrogen balance, a 24-hour urinary urea nitrogen collection is done. What do you also need to do?

Answer:

a) Pb(NO3)2 + 2KI ⇒ PbI2 + 2K(NO3)

ion that form the precipitate = Pb2+ and I-

Spectator ions = NO3. and K+

b) Pb 2+ + 2 I- ⇒ PbI2

Explanation:

The balanced chemical equation for the reaction of Lead(II) Nitrate and potassium iodide is 2 KI(aq) + Pb(NO3)2(aq) → 2 KNO3(aq) + PbI2(s). The precipitate forming ions are Pb2+ and I-, leading to the net ionic equation: Pb2+(aq) + 2I-(aq) → PbI2(s). The spectator ions are NO3- and K+.

When Lead(II) Nitrate reacts with potassium iodide, the balanced chemical equation becomes:
2 KI(aq) + Pb(NO3)2(aq) → 2 KNO3(aq) + PbI2(s)
The ions that form the precipitate in this reaction are Pb2+ from Lead(II) Nitrate and I- from Potassium Iodide. This results in the formation of Lead(II) Iodide, a yellow precipitate. The spectator ions, which do not participate in the formation of the precipitate, are NO3- from Lead(II) Nitrate and K+ from Potassium Iodide.
The net ionic equation therefore only includes the ions that form the precipitate, which are Pb2+ and I-. It becomes:
Pb2+(aq) + 2I-(aq) → PbI2(s).

https://brainly.com/question/29130807

#SPJ3

Answer:

The answer to your question is: Volume = 1.074 x 10⁻⁶ m³

Explanation:

Data

Salt crystal measures 5.44 x 10⁻² m ;  2.5 x 10⁻³ m;  7.9 x 10⁻³ m

From the information I suppose it is a cube, then,

Volume of a cube = length x width x height

Volume = 5.44 x 10⁻² m x  2.5 x 10⁻³ m x 7.9 x 10⁻³ m

Volume = 0.000001074 m³

Volume = 1.074 x 10⁻⁶ m³

Answer:

higher, left

Explanation:

Given that the reaction consumes 462 kJ of energy. It means that the reaction is a endothermic reaction.

In the energy profile of the endothermic diagrams, The reactants are at a very low level as compared to the products and hence, energy is supplied to overcome this difference.

Hence, The energy levels of products are higher than the energy level of reactant.

Hence, already stated, heat is required by the reaction and thus heat is written to the reactant side which is to the left side of the equation.

Answer:

The answer to your question is: the lasr one.

Explanation:

Ammonia = NH₃

It is tetrahedral because there are four bonded pairs around nitrogen.  This option is wrong, ammonia, does not have four bonds only has 3.

It is trigonal pyramidal because there are four bonded pairs around nitrogen.  This option is wrong because ammonia does not have 4 bonds.

It is tetrahedral because there are three bonded pairs and one lone pair around nitrogen.  A tetrahedral has 4 bonds not only three, this option is wrong.

It is trigonal pyramidal because there are three bonded pairs and one lone pair around nitrogen. This option is right, it has three bonded pairs and one lone pair around nitrogen so it is a trigonal pyramidal.

The statement that explains the VSEPR geometry of an ammonia molecule is ; ( D ) It is trigonal pyramidal because there are three bonded pairs and one lone pair around nitrogen.

    Ammonia ( NH₃ ) has a characteristic strong offensive smell and absence of water in its formation. It is very harmful when exposed to the environment. Ammonia has 3 bonded pairs and a single unpaired electron around nitrogen atom.

The Lewis structure of ammonia depicts a trigonal pyramidal structure because of the bonding of 3 hydrogen atoms to the Nitrogen atom and a lone pair

Hence we can conclude that  VSEPR geometry of an ammonia molecule is that it is trigonal pyramidal because there are three bonded pairs and one lone pair around nitrogen.

Learn more : https://brainly.com/question/15376539

Answer:

According with atomic weight and valences

Explanation:

Mendeleev organized the periodic table according atomic weight because the elements exhibit an apparent periodicity of properties, and the magnitude of the weight determines the character of the element

Answer:

The answer to your question is below: True

Explanation:

A double displacement reaction (replacement) is a reaction is which ions are interchanged to forms new compounds. Most of the times one of the products precipitates.

The general equation of this kind of reactions are:

                  AB + CD   ⇒   AD  +  CB

This is an example of this kind of reactions:

                AgNO3 + NaCl → AgCl + NaNO3

The given statement about the double displacement reaction has been true.

In the chemical reaction, the compounds have been dissociated into ions in the aqueous solution. The highly reactive ion will form the bond by displacing the less reactive ion. This type of reaction has been termed the single displacement reaction.

However, when there has been an exchange of the ions of two compounds in the aqueous solution, resulting in a new compound the reaction has been termed a double displacement reaction.

The reaction can be expressed as:

AX + BY [tex]\rightarrow[/tex] AB +XY

Thus, the given statement about the double displacement reaction has been true.

For more information about double displacement reaction, refer to the link:

https://brainly.com/question/2817852

Answer: 3 FeO + 2 Al -> 3 Fe + Al2O3

Explanation:

In order to verify if it is balanced or not you need to count the element at the left and the right. If they arent the same it isnt balanced.

And to balance the equation (simple method, not using redox) you assign coef 1 to the compound with more number of elements Al2O3 in this case and then you complete the rest

Answer:

The answer to your question is:

Explanation:

Data

carbon        7.3%          =     7.3g

hydrogen    4.5%         =      4.5g

oxygen       36.4%         =     36.4 g

nitrogen     31.8%         =     31.8 g

Now

For carbon

                    12 g --------------------1 mol

                    7.3 g     -------------     x

                       x = 7.3/12 = 0.608 mol

For hydrogen

                 1 g   --------------------  1 mol

                 4.5 g  ------------------    x

                   x = 4.5 mol

For oxygen

             16 g ------------------- 1 mol

             36.4 g ----------------    x

             x = 2.28 mol

For nitrogen

              14 g   ----------------   1 mol

              31.8 g ---------------    x

             x = 2.27 mol

Now divide by the lowest result, the is 0.608 from carbon

carbon              0.608/0.608 = 1

hydrogen           4.5/ 0.608 = 7.4

oxygen              2.28/0.608 = 3.75

nitrogen             2.27/0.608 = 3.73

Empirical formula = CH₇O₄N₄

For a compound with 7.3% carbon, 4.5% hydrogen, 36.4% oxygen, and 31.8% nitrogen, and a molecular mass of 176.0 g/mol, the empirical formula is CH7O4N4, and the molecular formula is CH9O5N5.

To find the empirical and molecular formulas of a compound with 7.3% carbon, 4.5% hydrogen, 36.4% oxygen, and 31.8% nitrogen, we start by assuming a 100g sample. This assumption simplifies the calculation since the percentages can directly translate to grams.

Next, we find the simplest whole number ratio by dividing each mole value by the smallest mole value calculated, which is for carbon.

The ratio simplifies to C: 1, H: 7, O: 4, and N: 4, giving us an empirical formula of CH7O4N4. The empirical formula mass (EFM) is calculated by summing the masses of all atoms in the empirical formula, which totals to 176 g/mol. Since the empirical formula mass matches the given molecular mass of 176.0 g/mol, the empirical formula CH7O4N4 is also the molecular formula.

To find the molecular formula, we need to compare the molar mass of the empirical formula with the given molar mass (176.0 g/mol) to find the "scaling factor" by which to multiply the empirical formula.

Calculate the molar mass of the empirical formula:

1 × 12.01 + 7 × 1.008 + 4 × 16.00 + 4 × 14.01 = 12.01 + 7.056 + 64.00 + 56.04 = 139.106 g/mol

Calculate the scaling factor:

Scaling factor = Molecular formula mass ÷ Molecular formula mass

Scaling factor = 176.0 ÷ 139.106

Scaling factor ≈ 1.264

Molecular formula: C1 × 1.264 H7 × 1.264 O4 × 1.264 N4 × 1.264

Molecular formula: C1.264 H8.848 O5.056 N5.056

Since we need whole numbers, we'll round these to the nearest whole number: CH7O4N4.

So, the empirical formula of the compound is CH7O4N4 and its molecular formula is CH9O5N5

Answer:

False

Explanation:

J. J. Thomson conducted an experiment which lead to the discovery of negatively charged particles only. He took a discharged tube and passed high voltage current through the gas and noticed that some particles from cathode is being emitted. They are fast moving particles and are deviated in the electrical and the magnetic field.

J. J. Thomson did not conclude anything about the positive charge. Hence, the statement is false.

Answer:

Oxidative phosphorylation yields a lot of ATP.

Explanation:

There are two types of respiration:

1. Aerobic respiration  

2. Anaerobic respiration

Aerobic respiration

It is the breakdown of glucose molecule in the presence of oxygen to yield large amount of energy. Water and carbon dioxide are also produced as a byproduct.

Glucose + oxygen → carbon dioxide + water + 38ATP

Anaerobic Respiration

It is the breakdown of glucose molecule in the absence of oxygen and produce small amount of energy. Alcohol or lactic acid and carbon dioxide are also produced as byproducts.  

Glucose→ lactic acid/alcohol + 2ATP + carbon dioxide

This process use respiratory electron transport chain as electron acceptor instead of oxygen. It is mostly occur in prokaryotes. Its main advantage is that it produce energy (ATP) very quickly as compared to aerobic respiration.  

Steps involve in anaerobic respiration are:

Glycolysis

Glycolysis is the first step of both aerobic and anaerobic respiration. It involve the breakdown of one glucose molecule into pyruvate and 2ATP.

Fermentation

The second step of anaerobic respiration is fermentation. It involve the fermentation of pyruvate into lactic acid or alcohol depending upon the organism in which it is taking place. There is no ATP produced, however carbon dioxide is released in this step.  Fermentation itself not produced ATP but produce in glycolysis step.

Answer:

The bond is planar. There is free rotation about the carbonyl carbon and nitrogen bond.

Explanation:

The peptide bond is planar and for this reason there is free rotation about the carbonyl carbon and nitrogen bond. Peptide bonds don't have double-bonds or delocalized electrons in their structure. Both oxygen and  nitrogen have a net negative charge on the peptide bonds.

A peptide bond is planar, does not allow free rotation due to its double-bond character, and has no net charge under physiological conditions.

The characteristics of a typical peptide (amide) bond are as follows:

https://brainly.com/question/35560541

#SPJ3

Answer:

Explanation:

lung air ways the mucus will clog it up causing asthma hope this helped :P

Answer: a. causes phelophtalein indicator to change from colorless to pink

Explanation:

Phenolphtalein is an indicator, which means it can visually change when given certain circumstances.

Phenolphtalein turns fuchsia when exposed to basic substances, especially above a pH of 8.2, due to ionization, which changes the structure of the indicator.

Answer:

The rate of decay of atoms (half-life) in container B is the same as the rate of decay of atoms (half-life) in container A.

Answer:

D. groups and periods

Explanation:

In groups  the elements have the same electronic configuration in the last electronic shell and we expect that they will have similar chemical properties.

In periods the electronic configuration is increasing with one electron as we proceed from left to right and so the chemical properties will vary significantly.

Answer:

The correct option is: an increase in body temperature due to high fever

Explanation:

Denaturation of protein is a process by which the protein unfolds i.e. loses it's quaternary, tertiary, and the secondary structure when exposed to high temperature (above 41°C), change in pH or chemical denaturants. Denaturation of proteins leads to loss of activity.

The enzymes pancreatic proteases breaks down proteins by hydrolysis, thus leading to the denaturation of protein.

Since, generally fever does not increase the body temperature above 41°C. Therefore, it doesn't lead to denaturation of protein.

Final answer:

Digestion by pancreatic proteases does not cause protein denaturation; it results in protein hydrolysis, which is the breakdown of proteins into amino acids. Protein denaturation can be reversible unless caused by irreversible changes such as cooking an egg white. Other factors causing denaturation include high temperatures, acidic conditions, and changes in pH.

Explanation:

Protein denaturation occurs when the structure of a protein is altered, leading to a loss of function. Factors that can cause denaturation include high temperatures from cooking, the presence of hydrochloric acid, changes in blood pH, and an increase in body temperature due to fever.

However, digestion by pancreatic proteases does not cause protein denaturation; instead, these enzymes are designed to operate in the digestive system and facilitate the process of protein hydrolysis, breaking down proteins into their constituent amino acids without denaturing them.

Thus, all of the listed conditions can cause denaturation, except for the digestion by pancreatic proteases, which actually serves a different purpose in the body. Protein denaturation is a delicate process, often reversible if the denaturing agent is removed, allowing the protein to resume its function. Some proteins, like those in bacteria that survive in hot springs, are adapted to function at high temperatures and do not denature easily, unlike the albumin protein in egg white which denatures irreversibly when cooked.

Answer:

1) 2.0 g

2) 0 g

3) 4.17 g

4) 2.57 g

Explanation:

First of all, we need to know the compounds and the reaction. The ion carbonate is [tex]CO3^{-2}[/tex], and the ion nitrate is [tex]NO3^{-}[/tex].

Sodium is in group 1, so it must lose one electron to be stable, and be the cation [tex]Na^{+}[/tex]. Silver has only one electron too, so the cation will be [tex]Ag^{+}[/tex].

To form the chemical compounds, first we put the cation, then the anion, and change their charges without the signal:

Sodium carbonate: Na2CO3

Silver nitrate: AgNO3

Silver carbonate: Ag2CO3

Sodium nitrate: NaNO3

The balanced reaction will be:

Na2CO3 + 2 AgNO3 --> Ag2CO3 + 2 NaNO3

Now, we must check the stoichiometry, which will be 1:2:1:2 (always in number of moles)

The question wants to know the mass value, so we need to know the molar mass of these compounds. Checking the periodic table will see that:

Na = 23 g/mol, C = 12 g/mol, N = 14 g/mol, O = 16 g/mol, Ag = 108 g/mol

So the molar mass of the compounds must be:

Na2CO3 = 106 g/mol (2x23 + 12 + 3x16)

AgNO3 = 170 g/mol (108 + 14 + 3x16)

Ag2CO3 = 276 g/mol (2x108 + 12 + 3x16)

NaNO3 = 85 g/mol

We have a mixture of the reactants, so one probably would be in excess, so, first will need to test. Let's do the stoichiometry calculus using silver nitrate as the limit, so:

1 mol of Na2CO3 ---------- 2 mol of AgNO3

106 g ------------------------------ 2x170 = 340 g

x ------------------------------------ 5.14 g

By a simple direct three rule:

340x = 544.84

x = 1.6 g of Na2CO3

That means that for this reaction, we only need 1.6 g of Na2CO3 to react with 5.14 of AgNO3. How we have 3.60 g of Na2CO3, it is on excess, and all the AgNO3 will be consumed.

1) The mass of Na2CO3 that remains after the reaction will be the initial less the mass that reacted:

m = 3.6 - 1. 6 = 2.0 g

2) All the AgNO3 reacted, so there isn't a mass present after the reaction.

m = 0 g

3) Now, doing the stoichiometry calculus between AgNO3 and Ag2CO3

2 moles of AgNO3 ------------- 1 mol of Ag2CO3

2x170 g ------------------------------- 276 g

5.14 g --------------------------------- x

By a simple direct three rule:

340x = 1418.64

x = 4.17 g of Ag2CO3

4) Now, doing the stoichiometry calculus between AgNO3 and NaNO3

2 moles of AgNO3 ----------------------- 2 moles of NaNO3

2x170 g ---------------------------------------- 2x85 g

5.14 g ------------------------------------------- x

By a simple direct three rule:

340x = 873.8

x = 2.57 g

2.0 grams of sodium carbonate, 0 gram of silver nitrate, 4.17 grams of silver carbonate and 2.57 grams of sodium nitrate is present after the reaction is complete.

We can calculate Number of grams or wanted weight through below expression:

[tex]\[{\rm{n = }}\frac{{\rm{W}}}{{\rm{M}}}\][/tex], where

n =  no. of mole

W = given weight

M = molar mass

In the question given balanced chemical reaction is:

[tex]${\rm{N}}{{\rm{a}}_{\rm{2}}}{\rm{C}}{{\rm{O}}_{\rm{3}}}{\rm{ + 2AgN}}{{\rm{O}}_{\rm{3}}} \to {\rm{A}}{{\rm{g}}_{\rm{2}}}{\rm{C}}{{\rm{O}}_{\rm{3}}}{\rm{ + 2NaN}}{{\rm{O}}_{\rm{3}}}$[/tex]

It is clear that mole ratio of reactant and product is 1:2::1:2.

Also mention that, given initial mass of sodium carbonate = 3.60g

And given initial mass of silver nitrate = 5.14g

In the reactant mixture one would be present in the excess quantity and we did stoichiometry calculation by assuming silver nitrate as the limiting reactant, so:

1 mole of Na₂CO₃ ............................. 2 mole of AgNO₃

106 g                     .............................. 2 × 170 = 340 g

x                            .............................. 5.14 g

Now by using simple three rule, we can calculate the value of x:

340x = 544.84

x = 1.6 g of Na₂CO₃

(1). Mass of Na₂CO₃ remains after the completion of reaction:

Initial - used = 3.6 - 1.6 = 2.0 g

(2). All the AgNO₃ get consumed by the excess Na₂CO₃, so mass present after completion of reaction is 0 g.

(3). Now again we will do stoichiometry calculation between AgNO₃ and Ag₂CO₃:

2 moles of AgNO₃ ............................ 1 mole of Ag₂CO₃

2 × 170 g                ............................. 276 g

5.14 g                     ............................. x

Now by using simple three rule, we can calculate the value of x:

340x = 1418.64

x = 4.17 g of Ag₂CO₃

(4). Again we will do stoichiometry calculation between AgNO₃ and NaNO₃:

2 moles of AgNO₃  .............................. 2 moles of NaNO₃

2 × 170 g                  .............................. 2 × 85 g

5.14 g                       ............................... x

Now by using simple three rule, we can calculate the value of x:

340x = 873.8

x = 2.57 g

Hence, amount of sodium carbonate, silver nitrate, silver carbonate and sodium nitrate is 2.0 g, 0 g, 4.17 g and 2.57 g respectively.

To learn more about moles, visit this below link:

https://brainly.com/question/1034638

Answer:

B is a precipitation reaction.

Explanation:

This is because a precipitation reaction is when a solid is made from the combination of cations and anions in a solution to create a solid.

[tex]\rm 2 NaI(aq) + Hg_2(NO_3)_2(aq) \rightarrow Hg_2I_2(s) + 2 NaNO_3(aq)[/tex] is a precipitation reaction. Therefore, the correct option is option B.

When two soluble compounds are combined, a precipitation reaction occurs, which is a sort of chemical reaction that creates an insoluble solid known as a precipitate. When two compounds mix to generate an insoluble compound that separates out as a solid from the solution, a precipitation reaction takes place.

The reactants in a precipitation reaction are typically ionic compound-containing aqueous solutions. The ions from the various chemicals may combine in these solutions to generate a complex that is only partially soluble. As a result, a solid precipitate that settles out of the solution is created. [tex]\rm 2 NaI(aq) + Hg_2(NO_3)_2(aq) \rightarrow Hg_2I_2(s) + 2 NaNO_3(aq)[/tex] is a precipitation reaction.

Therefore, the correct option is option B.

To know more about precipitation reaction, here:

https://brainly.com/question/11081618

#SPJ6

Answer:

P4+ 3O2 --->2P2O3

Explanation:

left side:

right side :

to balance:

Answer:

RNA

Explanation:

Oparin-Haldane hypothesis says that the life gradually arose from amino acids and then they combining to make the complex polymers.

Miller-Urey experiment provided first evidence that the organic molecules needed for the life could be formed from the inorganic components.

Currently, Scientists support RNA world hypothesis. It suggests that first life was the self-replicating RNA. Thus, RNA is vital molecule for the early life.

Answer:

Option C = 200 mL

Explanation:

The volume of liquid remain same because students just transfer the liquid from the graduated cylinder with the capacity 250 mL to the graduated cylinder having the capacity of 500 mL. The volume of the liquid will remain same either it is in the large graduated cylinder or in a small graduated cylinder.

Answer:

kL, dL, mL, pL

Explanation:

pL stands for picoliters. This is equal to 1 × 10⁻¹² (0.000000000001) liters.

mL stands for milliliters. This is equal to 1 × 10⁻³ (0.001) liters.

dL stands for deciliters. This is equal to 1 × 10⁻¹ (0.1) liters.

kL stands for kiloliters. This is equal to 1 × 10³ (1000) liters.

Answer:

[tex]\boxed{\text{\$0.07}}[/tex]

Explanation:

1. Convert cubic feet to litres

[tex]V =5.47 \times 10^{7} \text{ ft}^{3} \times \dfrac{\text{28.32 L}}{\text{1 ft}^{3}} = 1.549 \times 10^{9}\text{ L}[/tex]

2. Calculate the mass of vanillin

[tex]m = 1.549 \times 10^{9}\text{ L} \times \dfrac{2.0 \times 10^{-11}\text{ g}}{\text{1 L}} = \text{0.030 98 g}[/tex]

3. Calculate the cost of the vanillin

[tex]\text{Cost} = \text{0.03098 g} \times \dfrac{\textbf{\$115 }}{\text{50.0 g}} = \text{\$0.07}\\\text{The cost of the vanillin is $\boxed{\textbf{\$0.07}}$}[/tex]

The cost of the Vanillin is $0.07.

it is utilized in flavorings, foods, perfumes, and pharmaceuticals. Vanillin is used as a chemical intermediate in the manufacture of several essential pills and different merchandise. Human publicity to vanillin is through dermal contact with perfumes and ingestion of meal products that consist of vanillin as a flavor additive.

Vanillin is thought to release numerous substances whilst burnt. these consist of polycyclic fragrant hydrocarbons, that have been classed as human cancer-causing agents through the global corporation for studies on most cancers.

Learn more about Vanillin here: https://brainly.com/question/19338507

#SPJ2

The density of a hydrogen nucleus is approximately 1.24 x 10^17 kg/m^3, and the density of a hydrogen atom is approximately 8.38 x 10^16 kg/m^3.

To calculate the density of a hydrogen nucleus, we can use the formula for density, which is mass divided by volume. The mass of a proton is approximately 1.67 x 10^-27 kg, and the volume of a sphere can be calculated using the formula V = (4/3)πr^3. Let's assume the radius of a hydrogen nucleus is equal to the diameter of a proton, which is approximately 1.2 fm. Plugging these values into the formula, we can calculate the density of a hydrogen nucleus.

density = mass / volume = 1.67 x 10^-27 kg / ((4/3)π(0.6 x 10^-15 m)^3) = 1.24 x 10^17 kg/m^3

So, the density of a hydrogen nucleus is approximately 1.24 x 10^17 kg/m^3.

To calculate the density of a hydrogen atom, we need to know its mass and volume. The mass of an electron is approximately 9.11 x 10^-31 kg, and the volume of a sphere can be calculated using the formula V = (4/3)πr^3. Let's assume the radius of a hydrogen atom is equal to the given value, which is 1 x 10^-8 cm. Plugging these values into the formula, we can calculate the density of a hydrogen atom.

density = mass / volume = 9.11 x 10^-31 kg / ((4/3)π(0.5 x 10^-10 m)^3) = 8.38 x 10^16 kg/m^3

So, the density of a hydrogen atom is approximately 8.38 x 10^16 kg/m^3.

Answer: The correct answer is Option B.

Explanation:

Combustion reaction is defined as the chemical reaction in which a hydrocarbon reacts with oxygen gas to produce carbon dioxide gas and water molecule. The chemical equation for this reaction follows:

[tex]\text{hydrocarbon}+O_2\rightarrow CO_2+H_2O[/tex]

Incomplete combustion is defined as the reaction in which supply of oxygen is limited and carbon monoxide gas is also produced as a product. The chemical equation for this reaction follows:

[tex]\text{hydrocarbon}+O_2\text{(limited)}\rightarrow CO+CO_2+H_2O[/tex]

Single displacement reaction is defined as the reaction in which more reactive element displaces a less reactive element.

[tex]AB+C\rightarrow CB+A[/tex]

Element C is more reactive than element A.

As, we can see that oxides are the products in both complete combustion reaction and incomplete combustion reaction.

Hence, the correct answer is Option B.

Oxides are chemical compounds comprising of oxygen and another element. They're most often formed during combustion, where oxygen reacts with another substance to produce an oxide. One example is the burning of coal which produces carbon dioxide.

Oxides are chemical compounds that contain at least one oxygen atom and one other element. Most of the Earth's crust consists of solid oxides, the result of    elements being oxidized by the oxygen in the air. Option B, 'Products formed during combustion.' is the most accurate. During combustion, oxygen reacts with a substance, resulting in the production of an oxide. For example, when you burn coal (which is mostly carbon), carbon dioxide (CO2) is one of the products formed.

https://brainly.com/question/15578795

#SPJ3

Answer:

The correct option is A.

Explanation:

Isomers are molecules with the same formula but different structure. If you look at the previous structures and count the number of C and H, you find that  A and the molecule from the question has the same number of C and H, but their structures are different.

Answer:

B

Explanation:

I would go with B b/c C and D are wrong. The reason C is wrong is that buffers do get used up after a while so it wont be able to react indefinitely to maintain the pH and the reason D is wrong is that there are thousands of uses for buffer ranging from your own human body to thousands and thousands of things.

In my opinion, A is not necessarily wrong because buffer's job is to keep the pH of the solution relatively constant (up to some point), but I think B is still the best answer because it describes the actual function of buffer which is to resist pH.

Final answer:

Buffer solutions resist changes in pH when small amounts of acid or base are added. They protect other molecules from the effects of added acid or base and are critically important in biological systems.

Explanation:

A buffer solution is one which resists changes in pH when small amounts of acid or base are added. Buffer solutions contain both a weak acid and its conjugate base, or a weak base and its conjugate acid. By maintaining a relatively constant pH, buffers protect other molecules in the solution from the effects of added acid or base. These solutions are critically important in biological systems and can be obtained commercially.

Answer : The correct option is, (B) 12.8 ml

Explanation :

As we know that for the measurement of the volume of liquid in graduated cylinder are shown by placing the graduated cylinder on the flat surface and then view the height of the liquid in the graduated cylinder with the naked eyes directly level with the liquid.

The liquid will tend to curve downward that means this curve is known as the meniscus.

In the case of colored liquid, we are always read the upper meniscus of the liquid for the measurement.

In the case of colorless liquid, we are always read the lower meniscus of the liquid for the measurement.

In the given image, there are 10 division between the 12 and 13 and the smallest division is, 0.1. So, the volume of liquid will be, 12 ml + 0.8 ml = 12.8 ml.

Hence, the correct option is, (B) 12.8 ml

Answer:

To convert C to K, just add 273, remember that 0° C is 273 K, so 73.a) is 317.2 K and 73.c) is 253 K.  74.a) Will be, -129, 4 C + 273 = 143.5 F, 74.c) 663.8 F

75.a)  7.2 C , 75.c) -23.3 C

Explanation:

To convert C to F, you can use this, (9/5 * C + 32 ) = F, or back ward, C = (F - 32)* 5/9.