What is the molarity of a solution prepared by dissolving 12.0 g of potassium permanganate, KMnO4, in water to make 250.0 mL of solution

Answer:

a) Freezing and condensation

Explanation:

please mark me as brainliest

Answer:

1.0188 J/g*C

Explanation:

Using the formula; Q = m × c × ∆T

Q(water) = -Q(metal)

m × c × ∆T (water) = -{m × c × ∆T (metal)}

According to this question,

mass of metal = 25g

initial temp of metal = 99°C

mass of water = 50g

initial temp of water = 10.55°C

final temperature of the system = 20.15°C

c of water = 4.184 J/g*C

50 × 4.184 × (20.15 - 10.55) = 25 × c × (20.15 - 99)

209.2 × 9.6 = 25c × -78.85

2008.32 = -1971.25c

c = 2008.32 ÷ 1971.25

c of metal = 1.0188 J/g*C

Answer:

0.3323

Explanation:

GIven that:

Density of the metal = 10.6 g/cm^3

atomic weight = 176.8 g/mol

atmic radius = 0.130 nm

values of a and c = 0.570 nm and 0.341 nm respectively

For us to determine the atomic packing factor, we need to first determine the volume of all spheres (Vs) and the volume of unit cell (Vc).

However, the number of atoms  in the unit cell (n) can be computed as:

[tex]n = \dfrac{\rho * V_c *N_A}{A} \\ \\ n = \dfrac{(10.6) * (5.7)^2 (3.41)*(10^{-24}) *(6.022*10^{23})}{176.8}[/tex]

n = 4.0

Thus, the number of atoms in the unit cell is 4

∴

The atomic paking factor (APF) is calculated by using the formula:

[tex]\dfrac{Vs}{Vc} = \dfrac{4 * \dfrac{4}{3}\pi *R^3 }{a^2 *c} \\ \\ \\ \dfrac{Vs}{Vc} = \dfrac{4 * \dfrac{4}{3}\pi *(1.30*10^{-8})^3 }{(5.70*10^{-8})^2 *(3.41*10^{-8})}[/tex]

= 0.3323

We want to find the value of t such that the velocity vector makes an angle of 45° with both axes.

We found that:

t = (2/3)*(b/c)

The velocity vector makes an angle of 45° with the x and y axes.

We know that the position vector is:

r = r=b*t²i + c*t³j

Remember that the versor "i" corresponds to the x-component, and the versor "j" corresponds to the y-component, then:

r = r=b*t²i + c*t³j  = (b*t², c*t³)

The velocity vector is the vector that we get when we differentiate the position one, remember that if:

f(x) = a*x^n

then

f'(x) = n*a*x^(n - 1)

Using this, we can find that the velocity vector is:

v = (2*b*t,  3*c*t²)

Now we want to know, when does the velocity vector make an angle of 45° with the x and y axes.

Let's think of the vector as the hypotenuse of a triangle rectangle, where the x-component is the adjacent cathetus, and the y-component is the opposite cathetus. (so the angle is measured counterclockwise from the x-axis)

We have the trigonometric equation:

tan(a) = (opposite cathetus)/(adjacent cathetus)

So now we can replace these things with the known ones:

a = 45°

opposite cathetus = y-component = 3*c*t²

adjacent cathetus = x-component = 2*b*t

So we will get:

tan(45°)  =  (3*c*t²)/( 2*b*t)

1 = (3/2)*(c/b)*t

Now we can solve this for the variable, t.

1*(2/3)*(b/c) = t

t = (2/3)*(b/c)

We can conclude that at the time:

t = (2/3)*(b/c)

The velocity vector makes an angle of 45° with the x and y axes.

You can read more about vectors in:

https://brainly.com/question/10841907

Answer:

Carbon-14

Explanation:

It is because it have 6 protons and 8 neutrons which are added together to form an atomic mass of 14.

The mass number of an isotope is the sum of the number of protons and number of neutrons hence the correct answer is carbon-14.

Isotopes are atoms of the same element that has the same number of protons but different number of neutrons.

The atomic number is the same as the number of protons in the atom. Since there are six protons in the atom, the element must be carbon.

There are eight neutrons meaning that the mass  number is 8 + 6 = 14

Therefore, the isotope is carbon-14.

Learn more: https://brainly.com/question/13214440

Answer:

the answer is C

Explanation:

a molecule can be made up of two atoms of the same kind, as when two oxygen atoms bind together to make an oxygen molecule

I'd really appreciate a brainleast

Answer:

"[Temperature is a measurement of the average kinetic energy of the molecules in an object or a system. Kinetic energy is the energy that an object has because of its motion. The molecules in a substance have a range of kinetic energies because they don't all move at the same speed.]"

Answer:

Temperature is directly proportional to the average translational kinetic energy of molecules in an ideal gas

Explanation:

Answer:

K+ClKCl

Explanation:

because the reaction is between metal Potassium and Non-metal Chlorine

Answer:

Explanation:

a) It is a redox reaction because KCl is an ionic compounds with K having a + charge and Cl having a - charge. Originally, both have an oxidation state of 0 and not K has 1+ and Cl has 1-. Therefore, one species was oxidized and one was reduced which is indicative of a redox reactions.

b)

2K + Cl2 => 2KCl

The question is incomplete, the complete question is shown in the image attached to this answer

Answer:

2,3,3-trimethylhexane

Explanation:

IUPAC nomenclature provides a universally acceptable method of naming organic compounds from its structure.

According to this system of nomenclature;

A comma is used to separate two numbers.

A hyphen is used to separate a number from a letter.

Applying these rules, the name of the compound shown in the question should be written as 2,3,3-trimethylhexane.

В

an echo is caused by the fact that waves can be reflected by solid surfaces, this is due to the dynamic pattern of rarefactions and air seals near the reflecting surface

The third quantum number (m) describes the specific orbital within a sublevel. The correct answer is option D.

Quantum numbers are a set of four numbers that describe the properties of an electron in an atom. They specify the energy, position, and orientation of an electron in an atom.

The third quantum number (m) is also called the magnetic quantum number. It describes the orientation of the orbital in space. Each orbital within a sublevel has a different orientation in space, and the magnetic quantum number tells us which orbital we are talking about.

The value of m can range from -l to +l, where l is the second quantum number (the angular momentum quantum number). The value of l determines the number of orbitals in a sublevel, and the value of m determines the specific orbital within that sublevel.

In conclusion, the third quantum number (m) describes the specific orbital within a sublevel. It tells us how the orbital is oriented in space, and it can have values ranging from[tex]\rm -l \ to +l[/tex], where l is the second quantum number.

Option D is the correct answer.

Learn more about quantum number here:

https://brainly.com/question/32116992

#SPJ4

Answer:

» Water evaporating to gas.

» Solid subliming to gas.

» Water freezing to solid.

» Solid melting to liquid.

Explanation:

[tex]{ \underline{ \blue{ \sf{christ \:† \: alone }}}}[/tex]

Answer:

There are many reagents.

1. Use acidified potassium permanganate solution

2. Use acidified potassium dichromate solution

3. Fehling solution.

4. Silver/ oxygen at 500°C

5. Copper/ oxygen at 300°C

6. Lucas reagent ( anhydrous zinc and conc. hydrochloric acid)

Explanation:

Observations:

[with acidified potassium permanganate solution]

» Ethanol : The purple solution turns colourless.

» 2-methyl-2-propanol : no observable change.

[with acidified potassium dichromate solution]

» Ethanol : orange solution turns green

» 2-methyl-2-propanol : no observable change.

[Fehling solution]

» Ethanol : a white precipitate is formed

» 2-methyl-2-propanol : no observable change

Answer:

[tex]\boxed {\boxed {\sf 0.757 \ atm}}[/tex]

Explanation:

We are asked to find the pressure of a gas given a change in volume. Since the temperature remains constant, we are only concerned with volume and pressure. We will use Boyle's Law, which states the volume is inversely proportional to the pressure. The formula for this law is:

[tex]P_1V_1= P_2V_2[/tex]

Initially, the oxygen gas occupies a volume of 18.7 liters at a pressure of 1.19 atmospheres.

[tex]1.19 \ atm * 18.7 \ L = P_2V_2[/tex]

The gas expands to a volume of 29.4 liters, but the pressure is unknown.

[tex]1.19 \ atm * 18.7 \ L = P_2 * 29.4 \ L[/tex]

We are solving for the new pressure, so we must isolate the variable [tex]P_2[/tex]. It is being multiplied by 29.4 liters. The inverse operation of multiplication is division. Divide both sides of the equation by 29.4 L.

[tex]\frac {1.19 \ atm * 18.7 \ L}{29.4 \ L} =\frac{ P_2 * 29.4 \ L}{29.4 \ L}[/tex]

[tex]\frac {1.19 \ atm * 18.7 \ L}{29.4 \ L} =P_2[/tex]

The units of liters cancel.

[tex]\frac {1.19 \ atm * 18.7 }{29.4 } =P_2[/tex]

[tex]\frac {22.253}{29.4 } \ atm = P_2[/tex]

[tex]0.7569047619 \ atm =P_2[/tex]

The original measurements all have 3 significant figures, so our answer must have the same. For the number we calculated, that is the thousandth place. The 9 in the ten-thousandth place to the right of this place tells us to round the 6 up to a 7.

[tex]0.757 \ atm \approx P_2[/tex]

The pressure of the gas sample is approximately 0.757 atmospheres.

According to Boyle's law, for a given mass of ideal gas, pressure of gas is inversely proportional to the volume of gas, Provided the Temprature remains constant.

[tex]\implies \sf P_1 V_1 = P_2 V_2 \\ [/tex]

[tex]\implies \sf 1.19 \times 18. 7= P_2 \times 29.4 \\[/tex]

[tex]\implies \sf 22.253= P_2 \times 29.4 \\[/tex]

[tex]\implies \sf P_2 = \dfrac{22.253}{29.4} \\[/tex]

[tex]\implies \underline{ \red{\boxed{ \bf P_2 \approx0.756 \: atm }}} \\[/tex]

Calories, we know that fat burn is calories.

Answer:

1.28 M

Explanation:

Step 1: Given data

Mass of luminol (solute): 17.0 g

Volume of water: 75.0 mL (this is also the volume of solution)

Step 2: Calculate the moles corresponding to 17.0 g of luminol

The molar mass of luminol is 177.16 g/mol.

17.0 g × 1 mol/177.16 g = 0.0960 mol

Step 3: Calculate the molarity of the solution

We will use the definition of molarity

M = moles of solute / liters of solution

M = 0.0960 mol / 0.0750 L = 1.28 M

Answer:

Explanation:

Answer:

0.0922 g

Explanation:

Number of moles of acid present = 25/1000 × 0.0981

= 0.00245 moles

Number of moles of base = 5.83/1000 × 0.104

= 0.000606 moles

Since the reaction of HCl and NaOH is 1:1

Number of moles of HCl that reacted with antacid = 0.00245 moles - 0.000606 moles

= 0.001844 moles

From the reaction;

CaCO3 + 2HCl ----> CaCl2 + H2O + CO2

1 mole of CaCO3 reacts with 2 moles of HCl

x moles of CaCO3 reacts with 0.001844 moles ofHCl

x = 1 × 0.001844/2

= 0.000922 moles

Mass of CaCO3 = 0.000922 moles × 100 g/mol

= 0.0922 g

Answer:

See explanation and image attached

Explanation:

My aim is to convert 1-bromobutane to butanal. The first step is to react the 1-bromobutane substrate with water. This reaction occurs by SN2 mechanism to yield 1-butanol. Hence reagent A is water.

1-butanol is now reacted with an oxidizing agent such as acidified K2Cr2O7 (reagent B) to yield butanal. Note that primary alkanols are oxidized to alkanals.

These sequence of reactions are shown in the image attached.

Answer:

48.67 seconds

Explanation:

From;

1/[A] = kt + 1/[A]o

[A] = concentration at time t

t= time taken

k= rate constant

[A]o = initial concentration

Since [A] =[A]o - 0.75[A]o

[A] = 0.056 M - 0.042 M

[A] = 0.014 M

1/0.014 = (1.1t) + 1/0.056

71.4 - 17.86 = 1.1t

53.54 = 1.1t

t= 53.54/1.1

t= 48.67 seconds

Hence,it takes 48.67 seconds to decompose.

Answer:

1/2 the distance

Explanation:

If the viscosity of a solution is quadrupled then the distance of collection of diffusing molecules would be half over the same amount of time. The viscosity of the molecules is dependent on density of the liquid. It is independent to the volume of the liquid.

Answer:

A) Val-Gly-Arg-Ala-Val-Lys-Ala-Gly-Phe

B) Ala-Val-Lys-Val-Gly-Arg-Ala-Gly-Phe

Explanation:

The possible sequences that could be obtained from the available dat provided are :

A) Val-Gly-Arg-Ala-Val-Lys-Ala-Gly-Phe

B) Ala-Val-Lys-Val-Gly-Arg-Ala-Gly-Phe

Trypsin is generally a catalyst  for the breakdown of proteins into smaller peptides ( during the hydrolysis of peptide bonds )  

Answer:

Because a Lone pair of electrons on nitrogen is involved in delocalization.

Hope this helps you ( ◕ᴗ◕✿)

If it doesn't i'm sorry(◞ ‸ ◟)

Explanation:

In ethylamine ethyl is electron donating group. So more electrons are available aroudn nitrogen for donation. But in aniline phenyl group is electron attracting group.

Answer:

pH = 10.20

Explanation:

The HClO reacts with NaOH as follows:

HClO + NaOH → H2O + NaClO

Where HClO and NaOH react in a 1:1 reaction.

As the concentration of both reactions is the same and the reaction is 1:1, to reach equivalence point are required the same 25.0mL.

And the NaClO produced decreases its concentration in 2 because the volume is doubled.

The concentration of NaClO is: 0.150M / 2 = 0.075M

The equilibrium of NaClO is:

NaClO(aq) + H2O(l) ⇄ HClO(aq) + OH-(aq)

Where Kb of reaction is 1.0x10⁻¹⁴ / Ka =

1.0x10⁻¹⁴ / 3.0x10⁻⁸ = 3.33x10⁻⁷ = [HClO] [OH-] / [NaClO]

[NaClO] = 0.075M

As both HClO and OH- comes from the same equilibrium,

[HClO] = [OH-] = X

Where X is the reactoin coordinate

Replacing:

3.33x10⁻⁷ = [X] [X] / [0.075M]

2.5x10⁻⁸ = X²

X = 1.58x10⁻⁴M = [OH-]

pOH = -log [OH-]

pOH = 3.80

pH = 14 - pOH

Answer

Accordingly the order of electronegativity of the given elements would be: Fluorine > Chlorine > Bromine > Iodine. ( Fluorine has the highest electronegativity.)

Answer:

I think b acid makers

Explanation:

hope it will help you

The relative atomic mass of dihydrogen monoxide is 18g/mol

According to the periodic table:

Where; H = 1g/mol and O = 16g/mol

H2O = 1(2) + 16

= 2 + 16

= 18g/mol

Learn more at: https://brainly.com/question/17275626

Given concentration of NaCl=15%

Means ,

In every 100g of Solution 15g of NaCl is present .

Now

So ,

[tex]\\ \Large\sf\longmapsto 250\times 15\%[/tex]

[tex]\\ \Large\sf\longmapsto 250\times \dfrac{15}{100}[/tex]

[tex]\\ \Large\sf\longmapsto 37.5g[/tex]

37.5g of NaCl present in 250g of solution.

Answer:

Given concentration of NaCl=15%

Means ,

In every 100g of Solution 15g of NaCl is present .

Now

Given mass=250g

So ,

➡250 × 15%

➡250×15/100

➡37.5g

37.5g of NaCl present in 250g of solution.

Answer: The silver metal was OXIDIZED.

Explanation:

OXIDATION is defined as loss of electrons and increase in oxidation number of an atom.

Oxidation number is the charge on an ion in an ionic compound or the charge that an atom in a covalent compound would have it it were ionic. There are basic rules governing oxidation number, they include:

--> the oxidation number of elements in their free states is ZERO. Example O2, Cl2,Na, Al, Ag.

-->The oxidation number for an ion is the same as the size and sign of the charge on the ion. For example the oxidation number of Zn2+ is +2.

--> the sum of all the oxidation numbers of the elements in a compound is zero.

--> oxidation numbers are always written with either a positive or a negative sign.

On the other hand, reduction is the opposite of oxidation. As oxidation is taking place, reduction is also taking place. Reduction involves:

--> Gain of electron and

--> decrease in oxidation number

From the question, the silver metal had ZERO as it's oxidation number because it's in free state. After being exposed to oxygen to form silver oxide, the oxidation number became +1.

Since there is an increase in the oxidation number, the silver metal was OXIDIZED