Barium-142 is used as a GI radiocontrast agent. After 1.25 hours, 9.25 μg remains in the patient. Determine the original dose given the half-life of Ba-142 is 10.6 minutes.

Answer:

65 L is the volume of CO required

Explanation:

This is the reaction:

2CO (g) + O₂ (g) →  2CO₂ (g)

We must work with density to solve this problem

Density = Mass / volume

Let's determine the moles of O₂

1.43 g/mL = mass / 32500 mL

Notice, that we had to convert the volume from L, to mL, because the units of density.

Mass of O₂ → 1.43 g/mL . 32500 mL = 46475 g

Let's convert the mass to moles (mass / molar mas)

46475 g / 32 g/mol = 1452.3 moles

So ratio is 1:2

1 mol of oxygen needs 2 moles of CO, to react

Then, 1452.3 moles of O₂ would need the double of CO to react

1452.3 moles . 2 = 2904.6 moles of CO

This moles are contained in (mol . molar mass) =

2904.6 mol . 28 g/mol =81328.8 g

Density of CO = Mass of CO/ Volume of CO

1.25 g/mL = 81328.8 g / Volume of CO

81328.8 g / 1.25 g/mL  = 65063 mL

If we convert to L

65063 mL = 65.0 L

To react 32.5 liters of oxygen gas with carbon monoxide, the balanced chemical reaction shows a ratio of 2:1 between CO and O₂, thus requiring 65 liters of carbon monoxide.

The volume of carbon monoxide required to react with 32.5 liters of oxygen gas can be determined by looking at the coefficients in the balanced chemical equation of the reaction, which is not provided in the question but assuming a typical reaction between carbon monoxide and oxygen to form carbon dioxide, the equation is:

2 CO(g) + O₂(g) → 2 CO₂(g)

This equation shows that 2 volumes of CO react with 1 volume of O₂. Therefore, to find the volume of CO needed for 32.5 liters of O₂, you multiply the volume of O₂ by 2, because the ratio is 2:1.

The required volume of CO = 32.5 liters of O₂ × 2 (because of the ratio 2:1) = 65 liters of CO.

Answer:

T° freezing solution → -11.3°C

T° boiling solution → 103.1 °C

Explanation:

Assuming 100 % dissociation, we must find the i, Van't Hoff factor which means "the ions that are dissolved in solution"

This salt dissociates as this:

SnCl₄ (aq)  →   1Sn⁴⁺ (aq)  +   4Cl⁻  (aq)   (so i =5)

The formula for the colligative property of freezing point depression and boiling point elevation are:

ΔT = Kf . m . i

where ΔT = T° freezing pure solvent - T° freezing solution

ΔT = Kb . m . i

where ΔT = T° boiling solution - T° boiling pure solvent

Freezing point depression:

0° - T° freezing solution = 1.86°C/m . 1.22 m . 5

T° freezing solution = - (1.86°C/m . 1.22 m . 5) → -11.3°C

Boiling point elevation:

T° boiling solution - 100°C = 0.512 °C/m . 1.22 m . 5

T° boiling solution = (0.512 °C/m . 1.22 m . 5) + 100°C → 103.1 °C

In the nickel nucleus, the atomic number indicates the number of protons, and the mass number represents the sum of protons and neutrons. When nickel forms a +2 ion, the number of protons remains the same, but electrons decrease and neutrons increase to maintain electrical neutrality.

In the nickel nucleus represented above, the atomic number 28 indicates that the nucleus contains 28 protons, and therefore, it must contain 30 neutrons to have a mass number of 58.

When the nickel atom forms a +2 ion, it loses 2 electrons and becomes 60-Ni+2.

However, the number of protons remains the same at 28 because the atomic number defines the element.

Therefore, 60-Ni+2 still has 28 protons, but the number of electrons decreases to 26.

To maintain electrical neutrality, the ion gains 2 more neutrons resulting in 32 neutrons.

Answer: option 3. No, because Celsius is not an absolute temperature scale.

Explanation:

Answer:

3. No, because Celsius is not an absolute temperature scale.

Explanation:

Note that  20∘C=293K  and  5∘C=278K . So the absolute temperature has not decreased by very much at all, certainly not by a factor of four. Therefore, the change in size of the plastic bottle would not be very noticeable.

Answer:

Rock

Explanation:

Rock -

It refers to the substance composed of minerals which occurs naturally , is referred to as a rock.

Rocks are basically found in the outermost layer of the Earth i.e. , the crust .

There are three major type of rock known, i.e. , sedimentary rocks , metamorphic rocks and igneous rocks .

Hence, from the given information of the question,

The correct answer is rock.

A rock is a solid, naturally occurring, cohesive substance composed of minerals or mineral-like materials. Examples include granite which comprises various minerals. Rocks are classified into three types: igneous, sedimentary, and metamorphic.

A rock is a solid, naturally occurring, cohesive substance composed of minerals or mineral-like materials. For instance, granite is a common form of rock that comprises several minerals including feldspar, mica, and quartz. Rocks can be classified into three main types: igneous, sedimentary, and metamorphic, each type formed under different geological conditions and processes.

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Answer:

5.19 m³  

Explanation:

Data Given:

initial Pressure P1 = atmospheric pressure

Reported atmospheric pressure =  14.696 psi

Final pressures P2 =  68 psi

initial Temperature T1 =  26 °C

final Temperature T2 =  48 °C

initial Volume V1= 13 m³

final Volume V2 = ?

Solution:

Formula will be used

                    P1 V1 / T1 = P2 V2 / T2

To calculate volume rearrange the above formula

                   V2 = (P1 V1) T2 / T1 P2 . . . . . . . .(1)

put values in equation 1

                  V2 = (14.696 psi x 13 m³) 48 °C / 26 °C x 68 psi

                  V2 = (191.05 psi m³) 48 °C / 1768 °C psi

                  V2 = (9170.3  psi m³ °C / 1768 °C psi

                  V2 = 5.19 m³

So, final volume is 5.19 m³                

Answer:

C

Explanation:

The charge on an atom depends on the number of protons and electrons present in it. The protons in an atom are positively charged while electrons have a negative charge. For a neutral atom, the number of protons balances the number of electrons. for a negatively charged atom, the number of electrons is more than the number of protons. for a positively charged atom , the number of protons are more than the number of electrons.

An atom must have more protons than electrons in order to have a positive charge.

In order to have a positive charge, an atom must have more protons than electrons.

An atom is electrically neutral when it has the same number of electrons and protons. But if an atom has more protons than electrons, it will have an overall positive charge. For example, a dime has more protons than electrons, so it has a positive charge.

The positive charge of a proton is balanced by the negative charge of an electron. If an atom gains or loses electrons, it becomes an ion with a positive or negative charge.

Answer:

Mass of AgI formed=0.352g

Explanation:

AgNO3 + NaI ----‐>AgI + NaNO3

Volume of AgNO3 =5g/L

Mass of AgNO3 =C×V=0.25g

n(AgNO3)= m/Mr=0.0015mol

For NaI

V= 5g/l

Mass= C×v=0.25g

n=m/Mr=0.0017mol

n=0.0015mol

Mass=n× mr=0.352g

From the stoichiometry of the reaction, 0.45 g of AgI is formed.

First of all we have to obtain the molar concentration of AgNO3 using the formula;

Mass concentration = molar concentration × molar mass

Molar concentration = Mass concentration /molar mass

Molar concentration = 5.00 g/L/170 g/mol = 0.029 M

Number of moles of AgNO3  = molar concentration × volume

=  0.029 M  × 56.6/1000 L= 0.0016 moles

Molar concentration of NaI =  5.00 g/L /150 g/mol = 0.033 M

Number of moles of NaI = 0.033 M  × 56.6/1000 L = 0.0019 moles

The reaction equation is;

AgNO3 + NaI -----> AgI + NaNO3

Since the reaction is 1:1 then AgNO3 is the limiting reactant.

Mass of AgI formed = 0.0016 moles  × 235 g/mol = 0.45 g

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Answer:

A. 0.433 moles of HNO₃

B. 6.07×10⁻⁵ moles of NaCl

C.  3.51×10⁻³ moles of sucrose

Explanation:

Part A.

Molarity . volume = moles

1.70 mol/L . 0.255L = 0.433 moles

Part B.

1.35 m of NaCl means, a molal concentration (m). Moles of solute in 1kg of solvent.

Let's convert 1 kg to mg for the rule of three

1 kg = 1×10⁶ mg

So in 1×10⁶ mg of solvent, we have 1.35 moles of solute (NaCl)

In 45 mg, we would have ( 45 . 1.35) / 1×10⁶ = 6.07×10⁻⁵ moles of NaCl

Part C. 1.50 % by mass means, 1.50 g of solute, in 100g of solution.

Let's make a rule of three:

In 100 g of solution we have 1.50 g of sucrose

In 80 g of solution, we would have (80 . 1.50) / 100 =1.2 g of sucrose.

Then, let's convert the mass in moles ( mass / molar mass)

1.2 g / 342 g/m = 3.51×10⁻³ moles

(A) 0.433 moles of HNO₃ in 255mL of 1.70M HNO3

(B) 6.07×10⁻⁵ moles of NaCl in 45.0mg of an aqueous solution that is 1.35m NaCl

(C) 3.51×10⁻³ moles of sucrose in an aqueous solution that is 1.50% sucrose (C12H22O11) by mass

(A) 255mL of 1.70M HNO3(aq)

Molarity × volume = moles

1.70 × 0.255L = 0.433 moles of HNO3

(B) 45.0mg of an aqueous solution that is 1.35m NaCl

1.35 m of NaCl means, a molal concentration (m). Moles of solute in 1kg of solvent.

In 45 mg, the number of moles is:

45 × 1.35 / 1×10⁶ = 6.07×10⁻⁵ moles of NaCl

(C) 80.0g of an aqueous solution that is 1.50% sucrose (C12H22O11) by mass

the solute is 1.50 % by mass, that is :

1.50 g of solute, in 100g of solution.

In 80 g of solution

80 × 1.50 / 100 =1.2 g of sucrose.

Now, convert the mass in moles

number of moles = given mass / molar mass

1.2 g / 342 g/m = 3.51×10⁻³ moles of sucrose

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Answer:

a) 5.9846 mol/kg

b) 5.018 mol/L

c)0.09725

Explanation:

consider 100 g of solution

now

since the salt is 35 % , water will be 65 %

now

mass of salt = 35 g

mass of water = 65 g

we know that

moles = mass / molar mass

so

moles of salt = 35 g / 90 (g/mol) = 0.389 mol

moles of water = 65 / 18 = 3.6111 mol

now

volume of solution = mass of solution / density of solution

volume of solution = 100 g / ( 1.29 g/ml)

volume of solution = 77.52 ml

volume of solution = 0.07752 L

a)molality = moles of salt / mass of water (kg)

molality = 0.389 mol / 0.065 kg

molality = 5.9846 mol/kg

b)

molarity = moles of salt / volume of solution (L)

molarity = 0.389 mol / 0.07752 L

molarity = 5.018 mol/L

c)

now

total moles in the solution = moles of salt + moles of water

total moles in the solution = 0.389 + 3.6111

total moles in the solution = 4 mol

now

mole fraction of salt = moles of salt / total moles

mole fraction of salt = 0.389 mol / 4 mol

mole fraction of salt = 0.09725

The molarity of the solution is 5.018 mol/L and molality of the solution 5.9846 mol/kg.

Assume 100 g of solution the salt concentration- 35 % and water will be 65 %.    

So,  

mass of salt = 35 g  

mass of water = 65 g  

Number of moles,  

[tex]\bold {moles = \dfrac {mass} { molar\ mass}}[/tex]

So,    

moles of salt = 35 g / 90 (g/mol) = 0.389 mole  

moles of water = 65 / 18 = 3.6111 mole  

Volume of solution,

[tex]\bold {volume =\dfrac { mass } {density }}[/tex]  

volume = 100 g / ( 1.29 g/ml)  

volume of solution = 77.52 ml = 0.07752 L  

a)

[tex]\bold {Molality = \dfrac {moles\ of \salt} { mass\ of\ water (kg)}}[/tex]  

molality = 0.389 mol / 0.065 kg  

molality = 5.9846 mol/kg  

b)  

molarity = moles of salt / volume of solution (L)

molarity = 0.389 mol / 0.07752 L  

molarity = 5.018 mol/L  

c)    

 mole fraction of salt = moles of salt / total moles  

mole fraction of salt = 0.389 mol / ( 0.389 + 3.6111)  

mole fraction of salt = 0.09725

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Answer:

The answer to your question is letter E. 288.4 g/mol

Explanation:

Data

Number of carbons = 19

mass percent of carbon = 79.12

molar mass = ?

Process

1.- Calculate the molar mass of 19 atoms of carbon

Atomic mass of carbon = 12 g

Atomic mass of 19 atoms of carbon = 228 g                            

2.- Use proportions to calculate the mass of testosterone

                        228 g ---------------  79.12 %

                           x      --------------      100 %                          

                          x = (228 x 100) / 79.12

Simplify

                          x = 22800 / 79.12

Molar mass of testosterone = 288.2 g          

The options

Select one:

a. a 3- ion forms.

b. the noble gas configuration of argon is achieved.

c. the result is a configuration of 1s2 2s2 2p6.

d. the atom gains five electrons.

Answer:

c. the result is a configuration of 1s2 2s2 2p6.

Explanation:

Aluminium atom has atomic number of 13 , hence the number of electron is 13 for a neutral atom of aluminium. When aluminium atom reacts with other elements it usually gives out three electron to attain the octet configuration.

The cation representation of aluminium is Al3+ because it has loss three electron to attain the octet rule. Aluminium will be left with 10 electrons after losing 3 of it electrons. The electronic configuration will be represented as follows after losing three electrons;

1S² 2S² 2P∧6 .

At this stage the octet rule has been achieved as it will be represented as

2  8.  The first energy shell now contains two electron and the second energy shell contains 8 electrons.

The configuration of  Neon has been formed in the process.

Answer:

6 mol of A₂B₃ are produced

Explanation:

This is the reaction:

4A  + 3B₂  →  2A₂B₃

4 moles of A react with 3 moles of B to produce 2 moles of A₂B₃.

Ratio is 4:2. Therefore:

4 moles of A will produce 2 moles of A₂B₃

12 moles of A, would produce (12 .2) / 4 = 6 moles

By applying the stoichiometric ratios from the balanced chemical equation 4A + 3B2 -> 2A₂B₃, it's determined that reacting 12 moles of A with excess B₂ will result in the production of 6 moles of A₂B₃.

To solve this, we look at the balanced chemical equation given: 4A + 3B₂ -> 2A₂B₃. This equation tells us that 4 moles of A react with 3 moles of B₂ to produce 2 moles of A₂B₃. Using this ratio, we can set up a proportion to find out how many moles of A₂B₃ will be produced when 12 moles of A are used. Since 4 moles of A yield 2 moles of A₂B₃, 12 moles of A will yield:

(12 moles A / 4 moles A) * 2 moles A₂B₃ = 3 * 2 moles A₂B₃ = 6 moles A₂B₃.

Therefore, reacting 12 moles of A with an excess of B₂ will produce 6 moles of A₂B₃.

Answer : The density of a sample is, 34.2 g/L

Explanation :

Density : It is defined as the mass contained per unit volume.

Formula used for density :

[tex]Density=\frac{Mass}{Volume}[/tex]

Given :

Mass of a sample = 7.412 grams

Volume =0.217 L

Now put all the given values in the above formula, we get the density of a sample.

[tex]Density=\frac{7.412g}{0.217L}=34.2g/L[/tex]

Therefore, the density of a sample is, 34.2 g/L

Answer:

Below.

Explanation:

The reactions between sodium and chlorine.

2Na + Cj2 ---->  2NaCl.

1 electron from the sodium is transferred to the chlorine atom.

A simple chemical reaction involving the transfer of electrons from a metal to a nonmetal is the formation of sodium chloride from sodium and chlorine gas. This is an oxidation-reduction reaction where sodium is oxidized and chlorine is reduced, leading to the creation of an ionic compound.

An example of a simple chemical reaction that involves the transfer of electrons from a metallic element to a nonmetallic element is the reaction between metallic sodium and chlorine gas to form sodium chloride. This type of reaction is known as an oxidation-reduction or redox reaction. In the reaction, sodium, the metal, donates its electrons to chlorine, the nonmetal, resulting in the formation of sodium ions (Na⁺) and chloride ions (Cl⁻), which together form the ionic compound sodium chloride (NaCl).

The reaction can be represented by the equation:

2 Na (s) + Cl₂ (g) ⇒ 2 NaCl (s)

In this reaction, each sodium atom loses one electron (oxidation) to become a sodium ion, while each chlorine molecule gains two electrons (reduction) to form two chloride ions. The sodium cation (Na⁺) and the chloride anion (Cl⁻) then bond together to create the ionic compound sodium chloride.

The '2' in the chemical formula Mg₃(PO₄)₂ indicates that there are two phosphate groups for every three magnesium ions, forming the neutral ionic compound magnesium phosphate.

The chemical formula Mg₃(PO₄)₂ represents the compound magnesium phosphate. In this formula, Mg is the symbol for magnesium, and PO₄ is the polyatomic ion representing a phosphate group. The subscript '2' outside the parentheses indicates that there are two phosphate groups in the compound. When magnesium (Mg) has a 2⁺ charge and pairs with the phosphate ion (PO₄) that carries a 3⁻ charge, balancing the charges requires three magnesium ions to pair with two phosphate groups, resulting in the formula Mg₃(PO₄)₂. This substance is an example of an ionic compound where the constituents have different charges and combine in a ratio to form a neutral compound.

Thus, the '2' in the formula 5Mg₃(PO₄)₂ means that for every three magnesium ions, there are two phosphate ions. The leading '5' suggests that the entire formula is multiplied by five, indicating that there are five units of Mg₃(PO₄)₂ in the expression.

Answer:

The answer to your question is

1.- Volume = 3.4 ml

2.- Volume = 0.61 ml

3.- Mass = 2872.8 pounds

Explanation:

Problem 1

Volume = 18 ml

mass = 35.6 g

density = 10.5 g/ml

Process

1.- Calculate the volume of silver

Formula

[tex]density = \frac{mass}{volume}[/tex]

solve for volume

[tex]volume = \frac{mass}{density}[/tex]

Substitution

[tex]volume = \frac{35.6}{10.5}[/tex]

volume = 3.4 ml

2.- Problem 2

Total volume = ?

Volume = 18 + 3.4

Volume = 21.4 ml

Data

mass = 8.3 g

density = 13.6 g(ml

volume = ?

Formula

[tex]density = \frac{mass}{volume}[/tex]

Solve for volume

[tex]volume = \frac{mass}{density}[/tex]

Substitution

[tex]volume = \frac{8.3}{13.6}[/tex]

Result

volume = 0.61 ml

3.- Problem 3

Data

volume = 345 gal

density = 1 g/ml

mass = ?

Formula

[tex]density = \frac{mass}{volume}[/tex]

Solve for mass

mass = density x volume

Covert gal to ml

                            1 gal --------------- 3785 ml

                         345 gal -------------  x

                            x = (345 x 3785) / 1

                            x = 1305825 ml

Substitution

mass = 1 x 1305825

mass = 1305825 g

Convert g to pounds

                        1 g ------------------- 0.0022 pounds

              1305825 g ----------------   x

                        x = (1305825 x 0.0022)

                        x = 2872.8 pounds

Answer:

Explanation:

Light:

Solar Energy, Storage of Energy, Release of O2, & ATP

Dark:

CO2 Intake, Release of Energy, Release of Water, & Forms Carbohydrates.

Hope this helps!

Final answer:

In photosynthesis, solar energy is utilized during the light phase to produce ATP and release O₂, while the Calvin cycle (dark phase) involves CO₂ intake and the formation of energy-storing carbohydrates.

Explanation:

Photosynthesis consists of two main phases: the light reactions and the Calvin cycle (often referred to as the 'dark' phase). Here is the association of the given elements to each phase:

Light Phase Associations

Dark Phase (Calvin cycle) Associations

These associations help the processes involved in photosynthesis, where light energy is captured to produce ATP and NADPH, and then used along with CO₂ in the Calvin cycle to produce energy-storing carbohydrates, with O₂ released as a by-product.

Answer: we will solve it using Boyle's law that is:

P1V1 = P2V2

Explanation:

Substituting the given values

740 torr × 250 mL = 800 torr × V2

rearranging the equation for V2

740 torr × 250 mL / 800 torr = V2

'torr' in numerator cancelled by 'torr' in denominator

740 × 250 mL / 800 = V2

V2 = 231.24 mL

The volume of the oxygen gas will be approximately 231.25 mL at 800 torr, according to Boyle's law.

To answer your question, we can use Boyle's law, which states that the pressure and volume of a gas have an inverse relationship when the temperature is kept constant. In mathematical format, this is represented as P₁V₁ = P₂V₂, where P represents pressure, V represents volume, and the subscripts 1 and 2 represent the initial and final states, respectively. If we substitute the known values into the equation, we get (740. torr)(250. mL) = (800. torr)(V₂). By solving for V₂, we find that the new volume is approximately 231.25 mL.

Boyle's law and its implications are critical parts of understanding gas behavior, particularly in applications involving pressure and volume changes such as this one. Note that it's crucial to maintain a constant temperature for Boyle's law to be applicable, as stated in your question.

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Answer:

The answer to your question is 60 ml of solution 5% and 40 ml of solution 10 %

Explanation:

Data

acetic acid = 5% = concentration 1

acetic acid 2 = 10% = concentration 2

final solution = 7 % =

final volume = 100 ml

Process

1.- Write an equation of the process

x = volume of solution 5%

100 - x = volume of solution 10%

Final concentration x final volume = concentration 1 x volume 1 + concentration 2 x volume 2

      0.07(100) = 0.05x + 0.10(100 - x)

2.- Solve for x

                  7 = 0.05x + 10 - 0.1x

                 7 - 10 = 0.05 - 0.1 x

                   - 3 = -0.05 x

                     x = -3/-0.05

                     x = 60 ml of solution 5%

3.- Calculate the volume of solution 10%

     Volume of 10% = 100 - 60

     Volume of 10% = 40 ml        

Answer:

1000N is needed to be applied.

Explanation:

Machines make doing work easier. They allow us use small effort to carry out work on huge amount of load.

The mechanical advantage of a machine;

(M.A) =load/effort

M.A = 0.6

Load =600N

effort =?

0.6 = 600/effort

effort = 600/0.6

effort = 1000N

Answer:c

Explanation:

Answer:

C) When electrons change levels to produce the Balmer series, the emitted light is in the visible part of the spectrum

Explanation:

The Balmer Series of lines in the hydrogen atom was very important in the history of physics and astronomy. What made it so important?

A) It helped Rutherford explain the workings of the atomic nucleus.

B) Balmer's experiments with these lines helped prove Wien's Law.

C) When electrons change levels to produce the Balmer series, the emitted light is in the visible part of the spectrum.

D) The Balmer series of lines can only be observed from outer space; so the competition to see these lines led to the space race.

E) Mr. Balmer never got the Nobel prize, which made everyone in the field of spectroscopy so angry, they worked extra hard.

the most appropriate will be

C) When electrons change levels to produce the Balmer series, the emitted light is in the visible part of the spectrum

Balmer series of hydrogen lines. These lines are emitted when the electron in the hydrogen atom moves from the orbital n = 3 or greater shell down to the n = 2 shell/orbit. ... Energy is emitted from the atom when the electron leaps from one orbit to another closer to the nucleus.

Wiens law has to do with the radiation  of a black body.

The sample size is 233.19 mg and the purity of the sample is 48.97%

Why?

The chemical reaction between Na₂CO₃ and HCl is

Na₂CO₃ + 2HCl → 2NaCl + H₂O + CO₂

The sample size that will react with 40 mL of 0.1100 M HCl is found by applying the following conversion factor to go from L of solution of HCl to mg of Na₂CO₃:

[tex]0.04 Lsolution*\frac{0.1100molesHCl}{1L solution}*\frac{1 mole Na_2CO_3}{2 moles HCl}*\frac{105.99 gNa_2CO_3}{1 mole Na_2CO_3}*\frac{1000mg}{1 g}\\ \\=233.19mgNa_2CO_3[/tex]

Now, in order to find the percentage purity we have to apply another conversion factor to go from mL of solution of HCl to g of Na2CO3, and dividing everything over the mass of the soda ash sample, followed by multiplying the result times 100 to find the percentage:

[tex]0.04215 Lsolution*\frac{0.1100molesHCl}{1L solution}*\frac{1 mole Na_2CO_3}{2 moles HCl}*\frac{105.99 gNa_2CO_3}{1 mole Na_2CO_3}\\ \\=0.2457mgNa_2CO_3*\frac{100\%}{0.5017 g} = 48.97 \%\\[/tex]

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These chemistry problems involve calculating the moles of reactants in a stoichiometry equation to establish necessary sample size and the purity of a sample. By understanding these concepts, you can calculate the sample's purity and size.

The subject of this question is a stoichiometry problem, relating the amounts of reactants and products in a chemical reaction, and how to calculate a sample's purity. Stoichiometrically, each mole of sodium carbonate, Na2CO3, reacts with two moles of hydrochloric acid, HCl. Given the molarity of HCl (0.1100 M), you can calculate the number of moles by multiplying the molarity by the volume used in liters.

For the first question, it's given that the sample contains 40.00% Na2CO3. Therefore, the number of moles of HCl needed would be twice the number of moles of Na2CO3 (given that the reaction is 1:2). From there, you can calculate the required sample mass in milligrams.

For the second question, if it took 42.15 mL of 0.1100 M HCl to titrate a 0.5017 g sample, again calculate the moles of HCl used, and hence moles of Na2CO3. The mass of Na2CO3 is determined from its molar mass, and then the purity can be calculated as the mass of Na2CO3 divided by the total mass of the sample multiplied by 100%.

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Answer: metabolic acidosis.

Explanation:

Anion Gap(AG) is the difference between positively charged ions and negatively charged ions. It is usually expressed in milliequivalents per litre of millimoles per litres.

Anion Gap is measured or calculated when there is a need to know the cause of metabolic acidosis. To

Anion Gap can be calculated with or without potassium.

(1). With potassium= ([Na^+] + [K^+]) − ([Cl^−] + [HCO^−3]).

From the question; client's lab values are sodium 166 mEq/L, potassium 5.0 mEq/L, chloride 115 mEq/L, and bicarbonate 35 mEq/L.

Slotting in the values, we have;

==>[ (166+5) - (115+35)] mEq/L.

(2). Without potassium:

==> [Na^+] - ([Cl^−] + [HCO^−3]).

==> [(166) - 115 + (35)] mEq/L

Normal Anion gap is 20 mEq/L(Calculating with Potassium) and 8-16 mEq/L (calculating without potassium).

Answer:

D

Explanation:

the zero is trailing with a decimal so it counts. A is wrong because you can't round up, C is too many SF and E is wrong because a negative exponent would give you .001250

Answer: D

Explanation:

Not A: You don’t round up to 1251 because 3 is less than 5

Not B: That’s more than 4 sig figs

Not C: More than 4 sig figs

D: 1.250 has 4 sig figs and 1250 is the correct answer

Not E: negative exponent makes it into decimal which is way off

Answer:MnCO3+2H2O----->MnO2+ HCO3-+2e-+3H+

Explanation:The equation to be balanced is

MnCO3 ------> MnO2+HCO3-

The oxidation number of Mn changes from +2 in MnCO3 to +4 in MnO2

Therefore two electrons must be added to the right as shown below:

MnCO3 -------> MnO2+ HCO3-+ 2e-Now,there is one negative charge HCO3- and 1 negative charge on the two electrons making a total of -3 charges on the right. There is zero charge on the left.

To balance the equation,add3H+on the right,to cancel out the charges.

MnCO3 --------> MnO2+HCO3-+2e-+3H+

Adding H2O to balance Hydrogen and Oxygen atoms:

MnCO3+2H2O ------->MnO2+HCO3-+2e-+3H+

The half reaction for the oxidation of Manganese has been [tex]\rm MnCO_3\;+\;2\;H_2O\;\rightarrow\;MnO_2\;+\;HCO_3^-\;+\;2e^-\;+\;3\;H^+[/tex]

Oxidation has been defined as the loss of electrons by an element. The half reaction has been the oxidation reaction in the redox reaction.

In the reaction of Manganese carbonate to manganese dioxide, there has been change in the oxidation number of Mn from +2 to +4. The change in the oxidation state has been balanced with the addition of electrons.

The carbonate charge has been balanced in the reaction with the addition of hydrogen and water molecules.

The half reaction for the oxidation of Manganese has been [tex]\rm MnCO_3\;+\;2\;H_2O\;\rightarrow\;MnO_2\;+\;HCO_3^-\;+\;2e^-\;+\;3\;H^+[/tex]

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The standard enthalpy of formation of CaC2(s) can be calculated using the provided enthalpy of the reaction and the standard enthalpies of formation for the other substances participating in the reaction, which can be found in Appendix C.

In order to calculate the enthalpy of formation (ΔH∘f) for CaC2(s) from the given enthalpy of reaction data, we will use the thermochemical equation and the data from the appendix. The given reaction, CaC2(s)+2H2O(l)→Ca(OH)2(s)+C2H2(g), has an enthalpy of -127.2kJ.

Using this we can rearrange the equation to find the enthalpy of formation of CaC2(s) i.e. ΔH∘f (CaC2(s)) = ΔH∘reaction + ΔH∘f (Ca(OH)2) + ΔH∘f (C2H2) - [ΔH∘f (CaC2) + 2×ΔH∘f (H2O)].

To find ΔH∘f for CaC2(s), we need the values of standard enthalpy of formation of the other substances participating in the reaction, which can be found in Appendix C.

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Answer: B) an oxygen atom in a different molecule.

Explanation:

Hydrogen bonding (H-bonding) is an inter molecular force having partial ionic-covalent character.

H-bonding takes place between a hydrogen atom attached with an electronegative atom such as O, N and F and an electronegative atom such as O,N and F. They are strong forces.

Example: [tex]H_2O[/tex] has hydrogen bonding between hydrogen of one molecule with oxygen atom bonded to hydrogen of different molecule.

Thus the correct option is hydrogen bonding occurs between the hydrogen atom in one molecule and an oxygen atom in a different molecule.

In water, hydrogen bonding occurs between the hydrogen atom in one water molecule and the oxygen atom in a different water molecule. This is due to the large dipole moment caused by oxygen being more electronegative than hydrogen.

In a water molecule, hydrogen bonding occurs between the hydrogen atom of one molecule and an oxygen atom in a different molecule. Water molecules have a bent shape, with two hydrogen atoms and one oxygen atom. Because oxygen is more electronegative, the shared electrons between hydrogen and oxygen tend to stay closer to the oxygen atom, causing a dipole moment.

This dipole moment results in a partially positive charge on the hydrogen atoms and a partially negative charge on the oxygen atom. Hence, the hydrogen atoms from one water molecule are attracted to the oxygen atoms of another water molecule, forming hydrogen bonds.

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Answer:

The electrons are exposed to thermal energy/heat causing the excitation of the electron that is the electron in the outer orbital get absorbed and bounce to higher energy level.

Under the spectroscope, omitted wavelengths are seen with bright colors. For instance, light with longer wavelength appears red and light with shorter wavelength appear purple.

So, therefore, different metals will produce different wavelengths of light that are giving off a characteristic color of light.

Comparing the position of the colored light helps in the identification of substances.

When a substance is vaporized in a flame, the activity of electrons can be observed. The light emitted by the substance can be viewed through a spectroscope, which can help identify the substance based on its characteristic spectral lines or patterns.

When a substance is vaporized in a flame, the activity of electrons can be observed. This is because the high temperature of the flame causes the electrons in the substance to become excited and move to higher energy levels. When these excited electrons return to their ground state, they release energy in the form of light.

The light emitted by the substance can be viewed through a spectroscope, which is an instrument used to separate light into its different wavelengths or colors. By analyzing the specific wavelengths of light emitted, scientists can identify the substance based on its characteristic spectral lines or patterns.

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Answer:

This Question is incomplete

Explanation:

What is needed to be understood here is the concept of hypertonic and hypotonic solutions and their effects on cells.

Hypertonic solution is a solution in which the concentration of the solutes outside of the cell is greater than inside (in the cytoplasm) of the cell while hypotonic solution is a solution in which the concentration of solutes inside of the cell (in the cytoplasm) is greater than outside of the cell.

From the above, we can deduce that the question is about the effect of placing a prokaryotic cell in a hypertonic solution. When a prokaryotic cell is placed in a hypertonic solution, water moves (through osmosis) from inside of the cell to the outside environment causing the prokaryotic cell to shrink.

In a hypertonic solution, water will leave a prokaryotic cell through osmosis, causing it to shrink, which can interfere with its functions and lead to cell death if prolonged.

If a prokaryotic cell is placed in a solution that has a higher concentration of solutes than does the cytoplasm of the cell, the environment is described as being hypertonic. In this condition, the concentration of water outside the cell is lower than inside, leading to the net flow of water moving out of the cell. This process is known as osmosis. As water leaves the cell, it can cause the cell to shrink in a process termed plasmolysis. This can interfere with the cell's functions and potentially lead to cell death if the dehydration is prolonged. The cell wall in prokaryotes provides some protection against osmotic pressure, but the loss of water in a hypertonic solution still poses a significant challenge to the cell's viability.