. What mass of ammonium chloride must be added to 250. mL of water to give a solution with pH
4.85? [Kb(NH3) = 1.8 x 10-1
a. 4.7 g
b. 75 g
c.2.3 x 10-ºg
d. 19 g
e.10g

Answers

Answer 1

The mass of ammonium chloride that must be added is : ( A ) 4.7 g

Given data :

Volume of water ( V )  = 250 mL = 0.25 L

pH of solution = 4.85

Kb = 1.8 * 10⁻⁵

Kw = 10⁻¹⁴

Given that the dissolution of NH₄Cl gives NH₄⁺⁺ and Cl⁻ ions the equation is written as :

NH₄CI  +  H₂O  ⇄  NH₃ + H₃O⁺

where conc of H₃O⁺

[ H₃O⁺ ] = [tex]\sqrt{Ka.C}[/tex]   and Ka = Kw / Kb

∴ Ka = 5.56 * 10⁻¹⁰

Next step : Determine the concentration of H₃O⁺  in the solution

pH = - log [ H₃O⁺ ] = 4.85

∴ [ H₃O⁺ ] in the solution = 1.14125 * 10⁻⁵

Next step : Determine the concentration of NH₄CI in the solution

C = [ H₃O⁺ ]² / Ka

  = ( 1.14125 * 10⁻⁵ )² /  5.56 * 10⁻¹⁰

  = 0.359 mol / L

Determine the number of moles of NH₄CI in the solution

n = C . V

  = 0.359 mol / L  * 0.25 L =  0.08979 mole

Final step : determine the mass of ammonium chloride that must be added to 250 mL

mass = n * molar mass

         = 0.08979 * 53.5 g/mol

         = 4.80 g  ≈ 4.7 grams

Therefore we can conclude that the mass of ammonium chloride that must be added is 4.7 g

Learn more about ammonium chloride : https://brainly.com/question/13050932


Related Questions

Consider the gas phase reaction 4HCl + O2 → 2Cl2 + 2H2O. What volume of chlorine gas at STP can be prepared from the reaction of 600. mL of gaseous HCl, measured at STP, with excess oxygen?
a. 150 mL b. 267 mL c. 300 mL d. 425 mL e. 600 mL

Answers

Answer:

c

Explanation:

How many teaspoons are equal to 1 mole of water if there is 0.23 teaspoon for every 1 g?
A. 0.46 teaspoon
B. 3.68 teaspoons
C. 4.14 teaspoons
D. 18 teaspoons

Answers

Answer:it's b hope that help

The molar mass of water is 18 g. Given that there are 0.23 teaspoon for every 1 g. Thus , for 18 g there would be 4.14 teaspoons.

What is one mole?

Any substance that contains  6.022 × 10²³ number of atoms is called one mole of that substance. The mass of a compound or molecule containing these much atoms is called its molar mass.

Molar mass of water is 18 g. Thus, it means that one mole of water weighs 18 g. Given that for every 1 g of water there are 0.23 teaspoon. Thus, number of teaspoons for one mole or 18 g of water is:

number of teaspoons = 18 g × 0.23  /1 g

                                    = 4.14 teaspoons.

Therefore, 4.14 teaspoons are required for one mole of water.

To find more on molar mass, refer here:

https://brainly.com/question/12127540

#SPJ6

The F-C-F bond angle in the CH2F2 molecule is approximately __________.

Group of answer choices


180°


90°


120°


60°


109.5°

Answers

Answer:

109.5°

Explanation:

Pls Cross Check It, If It Correct

109.5° and it’s a Tetrahedral shape - a Carbon atom has 4 valence electrons and can share each electron with each of the 2 H atoms and 2 of the F atoms in order for them to form a full valence shell. This forms a 109.5° bond angle between F-C-F and all other atoms as the molecule experiences repulsion (atoms are trying to be as far apart as possible).

1. How many atoms are in 1.00 mole of H?

Answers

Answer:

6.022 × 1023

Explanation:

1 mole of H:

The definition of Avogadro's number of 6.022 × 1023/mole is the number of atoms or molecules per one gram atomic weight. For one gram atomic weight of hydrogen with an atomic weight of one gram, one mole of hydrogen contains 6.022 × 1023 hydrogen atoms. 1.45⋅6.02⋅1023≈8.73⋅1023 hydrogen atoms.

1 mole:

The value of the mole is equal to the number of atoms in exactly 12 grams of pure carbon-12. 12.00 g C-12 = 1 mol C-12 atoms = 6.022 × 1023 atoms • The number of particles in 1 mole is called Avogadro's Number (6.0221421 x 1023).

in an H:

H: 2×2×4=16 atoms of hydrogen. C: It only appears once and without a subscript, so 1×4=4 .  O : Like carbon, it's 1×4=4 .

1.00 mole:

One mole is equal to 6.02214179×1023 atoms, or other elementary units such as molecules.

Mark me brinilylist

What makes a cyclone rotate counter-clockwise north of the Equator and clockwise south of the Equator?
1 Ocean currents
2 Coriolis Effect
3 the Jet Stream
4 Landscape differences

Answers

The Coriolis Effect (Core-nol-e-us)

The ocean currents move differently on both equator‘s so it makes the cyclones rotate different

what is the mass in g of 7.009 x 10^21 molecules of Pl3?

Answers

I have completed the problem

natural gas has been stored in an expandable tank that keeps a constant pressure as gas is added or removed. the tank has a volume of 4.50x 104 ft 3 when it contains 77.4 million mole natural gas at - 5 °c. what is the new volume of the tank if consumers use up 5.3 million mole and temperature increase to 7 °c?

Answers

Answer:

5-3. Ice water 0 "C. A steel tank contains carbon dioxide at 27 "C and a pressure of 12.0 atm.

Explanation:

does the following atomic model of a chemical reaction correctly demonstrate the law conservation of matter why or why not plz help ​

Answers

Answer:

ZH² + O² = ZH²O I think this may help you I don't really know how to explain

A 6.00 L container of N_2 has a temperature of 273 K. Calculate the volume if the temperature is doubled.


a
24.0 L

b
12.0 L

c
6.0 L

d
3.0 L

Answers

V1/T1 =V2/T2 (using charles law)

V1=6.00
V2=?
T1=273
T2=273

Making V2 the subject of formula the equation then becomes

V2= V1xT2/T1

6.00x263/273=6.0L

4. The new element Plainsmenium (Pe) was discovered in 2005 by Monte E. Rey
(who will receive his Nobel Prize in Chemistry in the year 2012). It has
three isotopes: Pe-184 (24.60%), Pe-185 (11.20%), and Pe-188 (64.20%).
What is its average atomic mass?

Answers

This is my answer

Explanation:

p=m/v

where:. p=density

m=mass

v=volume

p=F/A = Lim F / A

1 ATM=14.7 psi

= 1.013x10 d/cm²

1 bar=10 d/cm²

=10 N/m2

Hope it helps to you goodluck

I'm not sure but that's the answer of my notebook like my answer please

Some insects, such as water striders, are able to walk on water. In one or two sentences, make and justify a conjecture about a property of water that would allow the insect to walk on it.(2 points) SHORT ANSWER

Answers

Insects can walk on water due to its surface tension, which is something like 0.07 J/m^2.

So water (and most liquids) have a property called surface tension, which is defined as the amount of energy that you need to increase the surface per area unit of the liquid volume.

Thus, if the insect has smaller energy than that, it would not change the surface of the liquid, allowing it to walk on the water's surface.

If you want to learn more about surface tension, you can read:

https://brainly.com/question/11348644

Answer: They are able to walk on water because of surface tension. Liquid molecules are held together by electrostatic forces. Molecules on the surface of the water are attracted to surrounding molecules and tension is created as the molecules get pulled down. This allows them to distribute their body weight over the water’s surface without breaking through that force.

Explanation:

I have a hard time telling the difference between convection, conduction, and radiation, anybody got any tips?

Answers

Conduction
In conduction, heat transfer takes place between objects by direct contact.

Convection

In convection, the heat transfer takes within the fluid.

Radiation

In radiation, heat transfer occurs through electromagnetic waves without involving particles.

please help
write the correct IUPAC name for these componds

Answers

Answer:

A. 4,6-dimethyloct-1,4,6-yne

B. deconic acid

C. 3-ethyl-4-methyl-7-bromocyclohexene

D. 2,2,3-trimethyl-4-butyl-heptane

E. 3-methylhexane

F. ethyl hexanoate

G. butanal

H. propyne

J. 2,4-dimethyl-pent-2-ene

Explanation:

sorry i didn't have time to do I

Gaseous methane reacts with gaseous oxygen gas to produce gaseous carbon dioxide and gaseous water. If 0.809g of carbon dioxide is produced from the reaction of 0.80g of methane and 2.1g of oxygen gas, calculate the percent yield of carbon dioxide.

Be sure your answer has the correct number of significant digits in it.

Answers

Answer:

About 58%.

Explanation:

We first need to write the balanced chemical equation:

[tex]\displaystyle \text{CH$_4$(g)} + 2\text{O$_2$(g)} \longrightarrow \text{CO$_2$(g)} + 2\text{H$_2$O(g)}[/tex]

We are given that 0.809 g of carbon dioxide was produced from the reaction of 0.80 g of methane and 2.1 g of oxygen gas. We want to calculate the percent yield of carbon dioxide.

First, determine the limiting reagent. We can convert each initial mass to the mass of carbon dioxide using stoichiometry. The molar mass of methane is 16.05 g/mol and the molar mass of carbon dioxie is 44.01 g/mol. From the equation, every one mole of carbon dioxide is produced from every one mole of methane and every two moles of oxygen gas.

0.80 g of methane will (theoretically) produce:

[tex]\displaystyle \begin{aligned} 0.80 \text{ g CH$_4$} &\cdot \frac{1 \text{ mol CH$_4$}}{16.05 \text{ g CH$_4$}} \cdot \frac{1 \text{ mol CO$_2$}}{1 \text{ mol CH$_4$}} \cdot \frac{44.01 \text{ g CO$_2$}}{1 \text{ mol CO$_2$}} \\ \\ & = 2.2 \text{ g CO$_2$}\end{aligned}[/tex]

2.1 g of oxygen gas will (theoretically) produce:

[tex]\displaystyle \begin{aligned} 2.1 \text{ g O$_2$} & \cdot \frac{ 1 \text{ mol O$_2$}}{32.00 \text{ g O$_2$}} \cdot \frac{1 \text{ mol CO$_2$}}{2 \text{ mol O$_2$}}\cdot \frac{44.01 \text{ g CO$_2$}}{1 \text{ mol CO$_2$}} \\ \\ & = 1.4 \text{ g CO$_2$} \end{aligned}[/tex]

Hence, oxygen gas is the limiting reagent. A maximum of 1.4 g of carbon dioxide can be produced.

To calculate the percent yield, we divide the actual yield by the theoretical yield. The actual yield was 0.809 g and the theoretical yield is 1.4 g. Hence:

[tex]\displaystyle \begin{aligned} \%\text{Yield} & = \frac{\text{Actual}}{\text{Theoretical}} \times 100\% \\ \\ & = \frac{(0.809\text{ g CO$_2$})}{(1.4\text{ g CO$_2$})} \times 100\% \\ \\ & = 58\%\end{aligned}[/tex]

In conclusion, the percent yield of carbon dioxide is about 58%.

Safety considerations
• Sodium Hydroxide (please insert one statement of caution from MSDS)

Answers

Answer:

d took the test

Explanation:

define conjugate Base and conjugate acid​

Answers

Explanation:

conjugated base is substance formed when an acid loses

a hydrogen ion.

conjugated acid is a type of acid that is formed when a base accepts a proton in solution

List these distance units in order from smallest to largest: nm,m,km,dm

Answers

Answer:

nm, dm, km, m

Explanation:

1 nanometer = 1e-12 (0.000000000001) kilometers

1 decimeter = 1e-4 (0.0001) kilometers

1 kilometer = 1 kilometer

Regardless of whether 'm' stands for mile or meter, it's still larger than all of these being approx. 1.61 and 1e-3 (0.001) kilometers respectively.

in the future, please provide the exact units.

Such as:

nanometers, decimeters, kilometers, meters

what is metal's I need answer ​

Answers

Answer:

objects thaty release 0H+ and H- ions when dissociated

Explanation:

in chemistry

please mark brainliest

Please give help and label them giving brainiest

Answers

Answer:

huh

Explanation:

calculate the number of molecules in 4.48dm3 of hydrogen at STP​

Answers

Answer: 1 more of hydrogen =22.4dm3

X moles of hydrogen =4.48dm3

22.4dm3x = 4.48dm3

4.48dm3\22.4dm3

X=0.2 moles

Explanation: 1 volume of hydrogen at STP is 22.4dm3

The N2O decomposition, 2 N2O (g) → 2 N2 (g) + O2 (g), is a zero order reaction that has a reaction rate constant of 2.00 × 10−3 M/s. Initially, 2.00 moles of N2O gas are infused into a 1.00 L vessel at 300. K.Calculate the pressure inside the vessel at 100. seconds after the start of the reaction. Temperature is held constant.

Answers

Answer:

2.00n2g

Explanation:

hope its attachments

2.
The highest part of the wave is called the ____________.
Group of answer choices

A. best

B. crest

C. top

D. trough

Answers

Answer:

B. crest

Explanation:

The highest part of a wavelength is called the crest, meanwhile, the lowest part is the trough.

Answer:

b

Explanation:

it's highest because it have the most higher wave

1. How does the figure below illustrate Hund's rule?

Answers

Answer:

it indicates that the lower orbitals are filled first and they have the maximum number of electrons compared to the higher orbitals

Which of these objects will most likely float?

Answers

Answer:

plastic,palstic bottle,balloon,cap of water bottle,plastic slippers and plastic comb.

Explanation:

hope it helps :D

0.1216 g
wire
All
g
of
20 mL of 1M HCl
neutralized by addition of 50 mL of 0.20 M NaoH
Find the Atomic mass of Mg ?
added
magnisium was added
the excess
acid
was

Answers

Keep Scrolling! :D

[tex] \rule{999pt}{66646pt}[/tex]

1. Which of the following shows the process of freezing?'
A.candle wax cooling on the table
B.pouring cola over ice
C.heating a cup of water
D.particles are speeding-up and colliding more

Answers

A, as the process of the wax getting cooler and hardening is it freezing. The other examples relate more to heating than freezing.

Electrolysis Is One of the Modern Technologies in Architecture’ Prepare an Investigatory Report That Supports the Statement”.​

Answers

Electrolysis is a technique that separates natural elements. It is commercially used to obtain important materials (e.g., pure metals) for construction.

Electrolysis refers to the use of an electric current to trigger non-spontaneous chemical reactions.

This technology (electrolysis) is commercially important in industry, construction and therefore also in architecture in order to extract metals and minerals from the ground.

Electrolysis uses particular electrolytic cells in order to extract highly pure metals from ores.

Learn more about electrolysis here:

https://brainly.com/question/12054569

Answer: Electrolysis is a technique that separates natural elements. It is commercially used to obtain important materials (e.g., pure metals) for construction.

Electrolysis refers to the use of an electric current to trigger non-spontaneous chemical reactions.

This technology (electrolysis) is commercially important in industry, construction and therefore also in architecture in order to extract metals and minerals from the ground.

Electrolysis uses particular electrolytic cells in order to extract highly pure metals from ores.

Learn more about electrolysis here:

brainly.com/question/12054569

Which element is shown below? How do you know?

Answers

It’s Neon (Ne). You know because there are 10 protons and the number of protons is equal to the atomic number of an element. (Neon is #10 on the periodic table)

what is the correct sequence of stages in cellular respiration

Answers

Answer:

Explanation:

Glycolysis

Pyruvic acid oxidation

Curbs cycle or citric acid cycle.

Respiratory chain.

Have a great night!

How how how how how

Hello Americans greetings from the Philippines ​

Answers

Answer:

good day philipines

Explanation:

Answer:

hello

Explanation:

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