A chemist weighed out 7.22 g of silver. Calculate the number of moles of silver she weighed out.
Be sure your answer has the correct number of significant digits.

Answer:

20 KG

Explanation:

Answer:

20 kg

Explanation:

F = ma

F = 280 N

a = 14 m/s^2

m = F/a = 280/14 = 20 kg

At STP, 1 mole of any gas occupies 22.4 L of space. Since we are given STP conditions here, we can use this ratio to determine the number of moles of CO gas: (32.8 L CO)/(22.4 mol CO/L CO) = 1.51 mol CO.

So, there are 1.51 moles of CO gas.

Answer: it think it would be last one.  the mouth to the stomach is the answer.

Explanation:

Answer:

The correct answer is D! The esophagus connects the mouth to the stomach.

Explanation:

The mouth is connected to the esophagus, which in turn is connected to the throat. The throat, in turn, connects the mouth to the stomach.

I had this on a science test and I got it right :D

I hope this helps! ;)

Answer:

Some natural resources like sunlight and wind are found everywhere, but other natural resources are unevenly distributed. Resources like oil, coal, and natural gas are only found where conditions were favorable to grow and preserve large quantities of animal or plant matter.

Explanation:

Answer:

[tex]30^{\circ}\text{C}[/tex]

Explanation:

To know the temperature at which KCl dissolves in water we need to refer to the general solubility curves.

In the case of [tex]KCl[/tex], [tex]35\ \text{g}[/tex] of it will dissolve in [tex]100\ \text{g}[/tex] of water at a minimum temperature of [tex]30^{\circ}\text{C}[/tex].

So, the the minimum temperature needed to dissolve 35 grams of KCl in 100 grams of water is [tex]30^{\circ}\text{C}[/tex].

Answer:

14.01 amu

Explanation:

Step 1: Given data

Isotope     Atomic mass (am)    Abundance (ab)

 ¹⁴N           14.00307 amu          99.64% (0.9964)

 ¹⁵N           15.0001 amu             0.36% (0.0036)

Step 2: Calculate the average atomic mass (aam) of nitrogen

We will use the following expression.

aam = ∑ am × ab

aam = 14.00307 amu × 0.9964 + 15.0001 amu × 0.0036 = 14.01 amu

Answer:

Option A, C, D

Explanation:

A reversible adiabatic process is an isentropic process as entropy remains constant. Thus,

Entropy change (Delta S) = integral of (Q_rev)/T

Thus, option A and C are correct

For a reversible process, entropy generation is a positive quantity or zero. hence, statement B is not true

In an Adiabatic processes, entropy do not decrease. Hence, option D is also correct

Answer:

0.083 M

Explanation:

We'll begin by calculating the number of mole in 0.43 g of KHP (potassium hydrogen phthalate, C₈H₅O₄K). This is can be obtained as follow:

Mass of C₈H₅O₄K = 0.43 g

Molar mass of C₈H₅O₄K = (8×12) + (5×1) + (16× 4) + 39

= 96 + 5 + 64 + 39 = 204 g/mol

Mole of C₈H₅O₄K =?

Mole = mass / molar mass

Mole of C₈H₅O₄K = 0.43 / 204

Mole of C₈H₅O₄K = 0.002 mole

Next, we shall determine the number of mole of NaOH required to react with 0.43 g (i.e 0.002 mole) of KHP. This can be obtained as follow:

C₈H₅O₄K + NaOH → C₈H₄O₄KNa + H₂O

From the balanced equation above,

1 mole of KHP reacted with 1 mole of NaOH.

Therefore, 0.002 mole of KHP will also react with 0.002 mole of NaOH.

Next, we shall convert 24.11 cm³ to L. This can be obtained as follow:

1000 cm³ = 1 L

Therefore,

24.11 cm³ = 24.11 cm³ × 1 L / 1000 cm³

24.11 cm³ = 0.02411 L

Finally, we shall determine the molarity of NaOH. This can be obtained as follow:

Mole of NaOH = 0.00 2 mole

Volume = 0.02411 L

Molarity of NaOH =?

Molarity = mole /Volume

Molarity of NaOH = 0.002 / 0.02411

Molarity of NaOH = 0.083 M

Answer:

[tex]H_{rxn}=-34.36\frac{kJ}{mol}[/tex]

Explanation:

Hello there!

In this case, according to the given information, it is possible to realize that the heat released by the reaction is used up to heat up the mixture, which means we can write:

[tex]-Q_{rxn}=Q_{sol}[/tex]

Whereas the Q of solution is given by the total mass (3.644+42.054), the specific heat of the solution and the change in temperature; thus, we obtain:

[tex]-Q_{rxn}=(3.644g+42.054g)*4.18\frac{J}{g\°C}*(36.2\°C-27.8\°C)\\\\ Q_{rxn}=-1604.55J[/tex]

Next, by computing the moles of the solute, we can proceed to compute the kJ/mol for the enthalpy of reaction (dissolution):

[tex]n=\frac{3.644g}{78.01g/mol}=0.0467mol\\\\H_{rxn}=\frac{Q_{rxn}}{n}\\\\ H_{rxn}=\frac{-1604.55J}{0.0467mol}*\frac{1kJ}{1000J}\\\\ H_{rxn}=-34.36\frac{kJ}{mol}[/tex]

Best regards!

Answer:

e. None of these.

Explanation:

Hey there!

In this case, since the Henry's law is defined in terms of pressure, henry's constant and pressure, as shown below:

[tex]C=K_H*P[/tex]

Whereas C is the concentration, KH the Henry's constant and P the pressure, we infer that the concentration of a gas solution is directly proportional to the pressure, which is not the group choices, therefore, the answer is e. None of these.

Best regards!

Answer:

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Answer:

0.917 L

Explanation:

Step 1: Given data

Step 2: Calculate the moles corresponding to 36.0 g of Ca(OH)₂

The molar mass of Ca(OH)₂ is 74.09 g/mol.

36.0 g × 1 mol/74.09 g = 0.486 mol

Step 3: Calculate the volume of the solution

Molarity is equal to the moles of solute divided by the liters of solution.

M = moles of solute / liters of solution

liters of solution = moles of solute / M

liters of solution = 0.486 mol / (0.530 mol/L) = 0.917 L

Answer:

0.917 liters

Hope this helps! :D

Explanation:

5.

(08.02 MC)

A 0.530 M Ca(OH)2 solution was prepared by dissolving 36.0 grams of Ca(OH)2 in enough water. What is the total volume of the solution thus formed? (4 points)

Answer:

I hope it's helpful for you....

Explanation:

Electrophilic substitution reactions are chemical reactions in which an electrophile displaces a functional group in a compound, which is typically, but not always, a hydrogen atom.

Answer:

2 NaBr(aq) + Cl₂(g) ⇒ 2 NaCl(aq) + Br₂(l)

Explanation:

Let's consider the unbalanced equation that occurs when aqueous sodium bromide reacts with chlorine gas to form aqueous sodium chloride and liquid bromine. This is a single displacement reaction.

NaBr(aq) + Cl₂(g) ⇒ NaCl(aq) + Br₂(l)

We will start balancing Cl atoms by multiplying NaCl by 2.

NaBr(aq) + Cl₂(g) ⇒ 2 NaCl(aq) + Br₂(l)

Then, we get the balanced equation by multiplying NaBr by 2.

2 NaBr(aq) + Cl₂(g) ⇒ 2 NaCl(aq) + Br₂(l)

Answer:

0.04 L (or 40 mL)

Explanation:

The dilution equation is: [tex]M_{s} V_{s} = M_{d} V_{d}[/tex]

[tex]M_{s}[/tex] = the molarity of the sock solution

[tex]V_{s}[/tex] = the volume of the sock solution

[tex]M_{d}[/tex] = the molarity of the diluted solution

[tex]V_{d}[/tex] = the volume of the diluted solution  

We are given the original, or stock, solution, which is [tex]M_{s} = 7.00 M NaOH[/tex], and [tex]V_{s} = 0.02 L (20 mL)[/tex]. We are also given the final molarity, which is: [tex]M_{d} = 3.5 M NaOH[/tex].

So, plugging our given into the dilution equation, results in:  

[tex]7.00 M * 0.02 L = 3.5M * V_{d}[/tex] (divide both sides by 3.5 M, in order to get [tex]V_{d}[/tex] by itself).

[tex]\frac{7.00 M * 0.02 L}{3.5M} = V_{d}[/tex]

[tex]V_{d} = 0.04 L (or 40 mL)[/tex]

So, the final volume of a 3.5 M NaOH solution, with an original solution of 20 mL of a 7.00 M NaOH solution, is 0.04 L (or 40 mL)

Hopefully this helped. Good luck!

Answer:

1.7 mol

Explanation:

This is an ideal gas problem. So many units! That's the tip-off usually.

PV=nRT

First convert kPA to atm 1 atm=101.3 kPA so 9.86/101.3 = .097311 atm

(.097311 atm x 500L) = n · 0821 L·atm/mol·K · 348K

Do your multiplication then divide to get n alone and you should get 1.7 mol

Answer:

Explanation: It is already known that 1 mole of the gas( or 32g of O2) is equivalent to 22.4 Litres of the oxygen gas. So, 8g is equivalent to = (22.4/32) × 8 = 5.6 L of the gas.

Answer:

Explanation:

This is due to multiple reasons. First of which, proper diet with a variety of selection of foods from vegetables, to dairy and meats can provide the body with essential nutrients used to fight off diseases and germs and improve the immune system. Exercise can also help boost the immune system and prevent diseases as well. It can also improve the condition of the heart which prevents heart disease and help the brain (prevent strokes). Drugs, smoking, alcohol and unsafe sexual activity can lead to a multitude of diseases, such as lung cancer, drug addictions, cardiac arrest, blood clots, HIV and other STDs, liver failure, etc. So it would be wise to abstain from those activities.

Answer:

605.6mg of quinine

Explanation:

Based on Lambert-Beer's law, the intensity of an optical measurement is directely proportional to its concentration.

Unknown concentration gives a reading of 327

100 ppm gives 180 of intensity

The concentration of the diluted quinine tablet is:

327 * (100ppm / 180) = 181.67 ppm. The final dilution

The concentration of the first diluted solution is:

181.67 ppm * (100.0mL / 15mL) = 1211ppm

ppm could be defined as mass of solute (In this case of quinine) in mg per liter of solution. That is:

1211mg / L

As the tablet was diluted to 500mL = 0.5L, the mass of the quinine is:

0.5L * (1211mg / L) =

Answer:

A. CO

Explanation:

This is the answer I believe based on that it has the least amount of elements leading me to think that it would have the least ionic character.

The compound that contains a bond with the least ionic character is CO.

Ionic bonding involves transfer of valency electrons. Usually from a metal to a non metal.

The ionic character or nature of a bond is determined by the relative

electronegativity of the atoms involved.

So, the bigger the difference between the electronegativity of two atoms, the more likely it is to be ionic.

This simply implies that if the electronegativity differences of the atoms

involved are smaller, the ionic character will be small.

Therefore, the  compound that contain a bond with the least ionic character is CO.

The difference in negativity of the carbon and oxygen atoms are small, this is

why the compound CO among the options possess the least ionic character.

learn more: https://brainly.com/question/19523724?referrer=searchResults

Answer:

B. NO₂, nitrogen dioxide

Explanation:

Nitrogen dioxide is one of the oxides of nitrogen. It reacts highly and is very harmful for the health of humans. It is regarded as one of the pollutants of the air pollution. The chemical formula of Nitrogen dioxide is NO₂. This gas is produced during the manufacturing of the fertilizers in the industries. Burning of the fossil fuels also contribute in the emission of nitrogen dioxide. Two atoms of oxygen when reacts with one atom of Nitrogen, Nitrogen dioxide is formed.

Answer:

B

Explanation: