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Answer:

b

Explanation:

base

This is the answer

Answer:

pH = 2.98

Explanation:

pKa of HNO2 is 3.35

HNO2 reacts with NaOH as follows:

HNO2 + NaOH → NaNO2 + H2O

Where moles of NaOH added are equal to NaNO2 produced

And initial moles of HNO2 - Moles NaOH = Moles HNO2

Initial moles HNO2:

0.0200L * (0.10mol/L) = 0.00200moles HNO2

Moles NaOH = Moles NaNO2:

0.0100L * (0.10mol/L) = 0.00100 moles NaOH = Moles NaNO2

Moles HNO2:

0.00200moles - 0.00100moles = 0.00100 moles HNO2

Then, the added HCl reacts with NaNO2 producing HNO2:

HCl + NaNO2 → HNO2 + NaCl

Where moles added of HCl are moles of HNO2 produced and initial moles  of NaNO2 - moles of HCl = Moles NaNO2

Moles HCl:

4x10⁻⁵L * (10.0mol / L) = 0.00040moles HCl = Moles of HNO2 produced

Moles HNO2:

0.00100moles + 0.0004moles = 0.0014moles HNO2

Moles NaNO2:

0.00100moles - 0.0004moles = 0.0006moles NaNO2

With these moles and H-H equation we can solve for the pH of the buffer:

pH = pKa + log [NaNO2] / [HNO2]

Where pH is pH of the buffer

pKa is pKa of HNO2: 3.35

[] are moles of each species:

Replacing:

pH = 3.35 + log [0.0006moles NaNO2] / [0.0014moles HNO2]

Answer:

a)

[tex]K_2=1.3x10^{2}atm^{-1/2}[/tex]

b)

[tex]PCl_5\rightarrow PCl_3+Cl_2[/tex]

[tex][PCl_5]=0.0375M[/tex]

Explanation:

Hello!

a) In this case, since we can see that the second reaction is equal to the half of the first reaction, we can relate the equilibrium constants as shown below:

[tex]K_2=K_1^{1/2}[/tex]

Thus, by plugging in the the equilibrium constant of the first reaction we obtain:

[tex]K_2=(1.6x10^4atm^{-1})^{1/2}\\\\K_2=1.3x10^{2}atm^{-1/2}[/tex]

b) In this case, for the described reaction we can write:

[tex]PCl_5\rightarrow PCl_3+Cl_2[/tex]

Thus, the corresponding equilibrium expression is:

[tex]K=\frac{[PCl_3][Cl_2]}{[PCl_5]}[/tex]

In such a way, since we know the equilibrium constant and the concentrations of PCl3 and Cl2 at equilibrium, we can compute the concentration of PCl5 at equilibrium as follows:

[tex][PCl_5]=\frac{[PCl_3][Cl_2]}{K}\\[/tex]

[tex][PCl_5]=\frac{\frac{0.20mol}{4L} *\frac{0.12mol}{4L} }{0.04}[/tex]

[tex][PCl_5]=0.0375M[/tex]

Best regards!

Answer:

its C, because the cocunut tree gets energy from the sun and makes it into cocunut that is true

Explanation:

its C, because the cocunut tree gets energy from the sun and makes it into cocunut that is true

Answer:

1. ether group R-O-R

2. benzene ring

3. 3°- alcohol

4.3°- amine group N attached to 3 groups rather than H

Answer:

For your first question, Curium does not occur naturally on Earth, meaning that it is not produced naturally on Earth. However, it can be formed in nuclear reactors.

For your second question, Curium has been used to provide power to electrical equipment used on space missions, but doesn't seem to be that important overall.

Explanation:

Hope this helped!

Answer:

The answer of 1×10 -8 is 2

Answer:

819.45 K

Explanation:

Use the Ideal Gas Law to make sense of this problem, PV = nRT. From this equation, we know that pressure is directly proportional to temperature and that volume is also directly proportional to temperature. Therefore, doubling the temperature would double the pressure, and doubling the temperature would also double the volume. In the described scenario, the temperature is doubled twice, so the temperature is quadrupled (i.e. three times its original amount has been added).

The initial temperature was 273.15 K. Multiply this by 3 to get your answer of 819.45 K.

13 half-lives have passed

General formulas used in decay:  

[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}[/tex]

T = duration of decay  

t 1/2 = half-life  

N₀ = the number of initial radioactive atoms  

Nt = the number of radioactive atoms left after decaying during T time  

t1/2 = 4 days

Nt=18 mg (0.01% of the original isotope)

18 mg (Nt) = 0.01% No

No = the original isotope :

[tex]\tt No=\dfrac{100}{0.01}\times 18~mg=180,000[/tex]

The duration of decay  (T) :

[tex]\tt \dfrac{Nt}{No}=\dfrac{1}{2}^{T/4}\rightarrow Nt=0.01\%No[/tex]

[tex]\tt 0.01\%=\dfrac{1}{2}^{T/4}\\\\10^{-4}=\dfrac{1}{2}^{T/4}\\\\(\dfrac{1}{2})^{13}=\dfrac{1}{2}^{T/4}\\\\13=T/4\rightarrow T=52~days[/tex]

Half-lives passed :

[tex]\tt \dfrac{52}{4}=13~half-lives[/tex]

Answer:

the pressure = 1937mmhg using standered unit of volume

Answer:

0.8333 L. P1v1=p2v2

Explanation:

I dont now if this is wht you were looking for so srry

The pressure of the gas at which the final volume of the gas has been 3 L has been 0.833 atm.

The gas has been assumed to be at constant temperature. The change in the pressure and volume of gas at constant temperature can be given by:

Initial pressure × Initial volume = Final pressure × Final volume

The initial pressure of gas has been 0.5 atm, and the initial volume has been 5L. The increased volume or final volume of the system has been 3 L.

The final pressure of the gas has been given by:

0.5 atm × 5 L = 3 L × Final pressure

Final pressure = 0.833 atm.

The pressure of the gas at which the final volume of the gas has been 3 L has been 0.833 atm.

For more information about the pressure of the gas, refer to the link:

https://brainly.com/question/6534127

Answer:

HNO3

Explanation:

HNO3 is nitric acid. Nitric acid as a compound contains Hydrogen, Nitrogen and Oxygen molecules, therefore its chemical formula is HNO3. Very useful for fertiliser and chemical making. This acid can be manufactured from ammonia and it is a very important chemical that is used for manufacturing fertilizers.

Nitric acid is useful for the manufacturing of ammonium nitrate and calcium ammonium nitrate which have uses as fertilizers.

Answer:

B. Inertia resist changes to the state of motion of a body.

Explanation:

The force of inertia is an inherent property of matter in which it allows a body to resist changes to the state of motion of the body.

According to Newton's first law of motion "a body will remain at rest or in constant motion unless if an external force acts on it".

This is the law inertia.

Answer:

F

Explanation:

A carousel can be made to rotate using different sources of energy.  One may decide to use electric energy, manual effort, water energy or heat energy as in a candle carousel.

When the candle is lit, heat energy is supplied and warm air rises heating up the air near the carousel eventually causing it to start rotating.

Hence heat from the candle leads to a current of warm air that rises up, causing the carousel to start rotating.

Answer:

1.4 x 10³

Explanation:

Given:

(3.5 x 10⁵)x(4 x 10⁻³)

Find:

Exponent form

Computation:

⇒ (3.5 x 10⁵)x(4 x 10⁻³)

⇒ 3.5 x 4 x 10²

⇒ 14 x 10²

1.4 x 10³

Answer:

Between the small pot and the book

Explanation:

Since gravitational force is influenced by the mass of an object, the higher the mass of two objects, the stronger the gravitational force.

Thus, the force between the pot and the book is strongest, since the two have the highest mass.

Have a nice day!

Answer:

Which is kinetic energy at its best, cause you are moving your arm or hand in motion, bu the object is in potential energy, where it isn't moving

Explanation:

The percentage composition of the alloy : 19.35% Zn, 80.65%Ag

Given

2.55 gram of an alloy

170 cc (170 ml=0.17 L) of  Hydrogen gas(H₂)

Ar Zn = 65. H=1

Required

The percentage composition

Solution

Silver remained unsolved⇒no reaction

Hydrogen gas from reaction of Zn

Zn+2HCl⇒ZnCl₂ + H₂

mol H₂ at STP (STP⇒1 mol = 22.4 L) :

[tex]\tt \dfrac{0.17}{22.4}=0.00759~moles[/tex]

From equation, mol ratio Zn : H₂ = 1 : 1, so mol H₂ = 0.00759

Mass Zn :

[tex]\tt mass=mol\times Ar\\\\mass=0.00759\times 65\\\\mass=0.49335~g[/tex]

Mass Silver :

[tex]\tt 2.55-0.49335=2.05665~g[/tex]

Percent composition :

[tex]\tt \dfrac{0.49335}{2.55}\times 100\%=19.35\%[/tex]

[tex]\tt \dfrac{2.05665}{2.55}\times 100\%=80.65\%[/tex]

Answer:

the answer Is d

Explanation:

or the last option is the answer if u need an explanation I may help u and tell me if u are from India

Answer:

dvis you're answer please like me

Answer:

The enthalpy of vaporization of H2O is higher than the enthalpy of fusion of H2O, therefore vaporizing the same mass of H2O would require more heat/energy than melting the same mass of H2O.

hope it helps!

Answer:52M

Explanation:

use S= 1000w/ MV

Here, s= molarity

w= the amount of NaCl

M= the atomic mass of NaCl

V= the volume of solution

Answer:

12.9 L Kr

General Formulas and Concepts:

Chemistry - Gas Laws

Explanation:

Step 1: Define

0.575 mol Kr

Step 2: Identify Conversions

1 mol= 22.4 L at STP

Step 3: Convert

[tex]0.575 \ mol \ Kr(\frac{22.4 \ L \ Kr}{1 \ mol \ Kr} )[/tex] = 12.88 L Kr

Step 4: Check

We are given 3 sig figs. Follow sig fig rules and round.

12.88 L Kr ≈ 12.9 L Kr

Answer:

Lithium is reduesednas it gains electrons gold

Answer:

Look at Lithium on the Periodic Table, look at the amount of electrons. When Lithium and Gold are together, Lithium loses while Gold(Au) gains.

Answer:

[tex]\displaystyle \frac{dh}{dt} = \frac{1}{10 \pi}[/tex]

Explanation:

Volume of a cone:

We have [tex]\displaystyle \frac{dV}{dt} = \frac{10 \ cm^3}{sec}[/tex] and we want to find [tex]\displaystyle \frac{dh}{dt} \Biggr | _{h\ =\ 6}= \ ?[/tex] when the height is 2 cm.

We can see in our equation for the volume of a cone that we have three variables: V, r, and h.

Since we only have dV/dt and dh/dt, we can rewrite the equation in terms of h only.

We are given that the height of the cone is 1/5 the radius at any given time, 1/5r, so we can write this as r = 5h.

Plug this value for r into the volume formula:

Differentiate this equation with respect to time t.

Plug known values into the equation and solve for dh/dt.

Divide both sides by 100π to solve for dh/dt.

The height of the cone is increasing at a rate of 1/10π cm per second.

Answer:

Mass =  11.16 g

Explanation:

Given data:

Mass of hydrogen = 8 g

Mass of oxygen = 10 g

Mass of water produced = ?

Solution:

Chemical equation:

2H₂ + O₂         →      2H₂O

Number of moles of hydrogen:

Number of moles = mass / molar mass

Number of moles = 8 g/ 2 g/mol

Number of moles = 4 mol

Number of moles of oxygen:

Number of moles = mass / molar mass

Number of moles = 10 g/ 32 g/mol

Number of moles = 0.31 mol

now we will compare the moles of hydrogen and oxygen with water.

                   O₂          :           H₂O

                    1            :             2

                  0.31         :            2/1×0.31 = 0.62

                  H₂           :            H₂O

                    2            :              2

                     4            :              4

Number of moles of water formed by oxygen are less this it will act as limiting reactant.

Mass of water:

Mass = number of moles × molar mass

Mass = 0.62 mol × 18 g/mol

Mass =  11.16 g

Explanation:

giving equal opportunity,making good governance, maintaining peace and harmony among people, other try to write by your self

first we find the mass of the final solution

we know that

density=mass/volume

we know the density and volume

1=m/100

m=100g

now we calculate the mass ofNa2CO3

2% of 100 is equal with 2g of Na2CO3

Answer:Multiple the moles of Na2 SO4 that you found just

Explanation:

Ions are formed by gaining and donating the valence electrons from the outer shells. Sodium has an extra electron and forms cations. In 1.5 grams of Na⁺, there are 0.0652 moles ions.

Cations are said to be the ions that are formed by donating electrons from their valence shell. They tend to donate their electrons to form ionic bonds with another atom that accepts the electrons.

The mass and the molar mass of the cation can be used to calculate the number of moles contained in the atom or the ion.

Given,

Mass of sodium ions = 1.50 grams

The molar mass of sodium ions = 22.98 amu

The number of moles of sodium cation is calculated as:

Moles (n) = mass ÷ molar mass

n = 1.50 ÷ 22.98

= 0.0652 moles

Therefore, 0.0652 moles are present in 1.50 grams of sodium ions.

Learn more about cations, here:

https://brainly.com/question/13691496

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