Why BF3 acts as a Lewis acid???

Answer:

[tex]0.016\frac{g}{L}[/tex]

Explanation:

Hello,

In this case, the dissociation of calcium fluoride is:

[tex]CaF_2(s)\rightleftharpoons Ca^{2+}(aq)+2F^-(aq)[/tex]

And the equilibrium expression is:

[tex]Ksp=[Ca^{2+}][F^-]^2[/tex]

Which is useful to compute the molar solubility, symbolized by [tex]x[/tex] as the reaction extent:

[tex]Ksp=(x)(2x)^2[/tex]

In such a way, since the solubility product of calcium fluoride at 25 °C is 3.45x10⁻¹¹, the molar solubility is found to be:

[tex]3.45x10^{-11}=(x)(2x)^2\\\\x=\sqrt[3]{\frac{3.45x10^{-11}}{4} }\\ \\x=2.05x10^{-4}M=2.05x10^{-4}\frac{molCaF_2}{L}[/tex]

And the solubility, considering its molar mass 78.08 g/mol is:

[tex]=2.05x10^{-4}\frac{molCaF_2}{L}*\frac{78.08gCaF_2}{L}\\ \\=0.016\frac{g}{L}[/tex]

Regards.

Answer:

11.32cm

Explanation:

This question describes a cylinder rod formed from silicon with length 21.3cm and mass 5kg. The density of the silicon is 2.33g/cm3.

To calculate the diameter, the radius is needed. To calculate the radius, the volume is needed. To calculate the volume, the formula: density = mass (m) / volume (V) is used.

Mass = 5kg, which is 5 kg × 1000g = 5000g

Density= 2.33g/cm3

Hence; volume= mass / density

= 5000/2.33

= 2145.9 cm3

Volume of cylinder= πr^2h

Where h= 21.3cm and π= 3.142

That is; r^2 = volume/πh

= r^2 = 2145.9/3.142×21.3

= r^2 = 2145.9/66.9246

= r^2 = 32.06

r= √32.06

r= 5.66cm

If radius of the cylinder is 5.66cm, the diameter is twice of the radius.

That is, diameter (d) = 5.66 × 2

= 11.32 cm

Therefore, the diameter of the cylinder is 11.32cm.

Answer:

Here's what I get  

Explanation:

The modern periodic law states that the physical and chemical properties of the elements are periodic functions of their atomic numbers.

[tex] \LARGE{ \underline{ \purple{ \bf{Required \: answer:}}}}[/tex]

When everything wasn't discovered yet....The Scientists gave different opinions and ways to classify the elements discovered in their time.

Modern Periodic table was the most accepted model for arranging the elements on the basis of their Atomic number. So, we can also say that they are also dependent upon the electronic configurations of those elements. It was put forward by Moseley.

#KeepOnExploring

Answer:

The Hydrogen gas produced during its reaction with metal gets oxidised to H2O, hence no hydrogen gas is produced. Instead it evolves nitric oxides such as NO2,NO etc.

Answer: bright red light

Explanation:

im taking edge

Answer:

The reference point is the ground.

Explanation:

•Moves slow that you don't notice hope this helps you :) god loves you :)

Answer:

1406136 grams

Explanation:

Answer:

A process in which a chemical change, especially decomposition, is brought about by passing an electric current through a solution of electrolytes so that the electrolyte's ions move toward the negative and positive electrodes and react with them.

Answer:

a pgsysyyssysyysysyshshshshshshshshshshshshshss

Answer:

translate? ill edit this later

Explanation:

Answer:

1)[tex]Time \ for \ pendulum \ swing \ left \ and \ right = 2 \times \pi \times \sqrt{\dfrac{Length \ of \ the \ pendulum \ string}{g} }[/tex]

2) The dependent variable = The time it takes for one pendulum swing

3) The independent variable = The length of the pendulum string with weight at the bottom

Explanation:

The relationship between the length of the pendulum string and the time it takes for one pendulum swing is giving as follows;

[tex]T = 2 \cdot \pi \cdot \sqrt{\dfrac{L}{g} }[/tex]

Where;

T = The period of oscillation = The time to complete one oscillation =Two swings of the pendulum

L = The length of the pendulum

g = The acceleration due to gravity

Therefore, the time it takes for one pendulum swing is directly proportional to the square root of the length of the pendulum

The dependent variable = The time it takes for one pendulum swing

Th independent variable = The length of the pendulum string with weight at the bottom.

Answer:

Fundamental quantities or base quantities are:

✔️Lengthy

✔️Mass

✔️Time

✔️ Temperature

✔️Electric current

✔️Amount of substance

✔️Intensity of light

Explanation:

Hope it will help you :)

Answer:

According to Thompson's model, Every atom consists of a positively charged sphere of radius 10-- 10m in which entire mass and positive charge of the atom are uniformly distributed inside the sphere electrons are embedded like seeds in watermelon. According Rutherford entire poistive charge and mass of the atom are concentrated in a tiny central core of the atom which is called atomic nucleus contains. Size of nucleus = 10-- 15m. The nucleus contains protons and neutrons. Negatively charged electrons revolve around the nucleus in circular orbits.

Explanation:

Answer:

A

Explanation:

Answer:

The correct answer is B. Liquids have less energy than solids.  This is false because liquids have more energy than solids; the particles in a liquid are moving whereas the particles in a solid are almost still (they may vibrate slightly).  This increase in speed of particles translates to kinetic energy, showing us that liquids have more energy than solids.

Explanation:

We can also examine the other answer choices and show why they are incorrect.

Solids have a definite volume and shape.  Think about solids in your house; for example, think about a chair or a block.  The shape of these items cannot be changed, and their volume is unchanging.

There are no intermolecular forces between the particles of a gas. This is assumed to be a property of an ideal gas, which makes sense since the particles in a gas are farther from each other than those in a liquid or a solid.'

Sublimation occurs when a solid turns into a gas.  This is also a true statement; when a solid sublimes, it changes into a gas without ever becoming a liquid.

Hope this helps!

Answer:

the four main spheres of the earth are geosphere, hydrosphere, atmosphere and biosphere

Explanation:

geosphere consists of all rocks on Earth

atmosphere which are the gases that surrounds the earth

hydrosphere which is all the water on the earth

biosphere which are the living things on the earth

Answer:

touched touched

Explanation:

rusting can occure

sonority may take place

Answer:

343.2 miles

Explanation:

To find the miles that you can travel with 13.2 gallons of gas, you can use a rule of three given that you know that the car gets 26 miles to the gallon:

    1 gallon   →   26 miles

13.2 gallons →        x

x=(13.2*26)/1

x= 343.2

According to this, the answer is that you can travel 343.2 miles.

Answer:

Ver respuesta abajo

Explanation:

En este caso, para saber el tipo de reacción de cada uno, necesitamos saber los tipos de reacción, que en este caso son los siguientes:

a) Combinación  (C): Tan sencillo como que tengo 1 elemento o compuesto, que se combina con otro elemento o compuesto, formando uno nuevo:

A + B ----> AB

b) Desplazamiento (D): aquí un elemento reemplaza a otro en un compuesto, formando un compuesto nuevo:

A + BC ----> AC + B

c) Descomposición (Ds): Es lo opuesto a combinación. Un compuesto se descompone o se separa en dos o mas elementos básicos por efecto del calor o electricidad:

AB ----> A + B

d) Doble desplazamiento (DD): en este caso, dos elementos de compuestos diferentes se intercambian, formando nuevos compuestos:

AB + CD ------> AC + BD

Siguiendo estos pequeños conceptos, veamos el tipo de reacción de cada reacción puesta:

1. Mg + H2SO4 ----> MgSO4 + H2   (D) (Mg desplaza al H2)

2. 2KI + Pb(NO3)2 ----> PbI2 + 2KNO3 (DD) (K y Pb intercambian compuestos)

3. 2Zn + O2 ----> 2ZnO (C) (se unen el Zn y el O)

4. Zn + CuSO4 ---->ZnSO4 + Cu (D) (Zn reemplaza al Cu)

5. Na2CrO4 + 2AgNO3 ----> NaNO3 + Ag2CrO4  (DD) (Na y Ag forman dos compuestos nuevos)

6. 2H2O ----> 2H2 + O2  (Ds) (El agua se separa en dos elementos)

7. SO3 + H2O ----> H2SO4  (C) (se formó un nuevo compuesto)

8. HCl + NaOH ----> NaCl + H2O  (DD) (Na y H formaron dos compuestos nuevos)

9. Cl2 + KBr ----> 2KCl + Br2  (D) (Cl reemplaza al Br)

10. CaCO3 ----> CaO + CO2  (Ds) (CaCO3 se separó en dos compuestos)

Answer:

18 electrons

Explanation:

If you search on Google you get the same answer, so the question gives you your answer.

Answer: Explanation:

A unit prefix is a specifier or mnemonic that is prepended to units of measurement to indicate multiples or fractions of the units.

Units of various sizes are commonly formed by the use of such prefixes.

The prefixes of the metric system, such as kilo and milli, represent multiplication by powers of ten.

Answer:

see below

Explanation:

A unit prefix is a specifier or mnemonic that is prepended to units of measurement to indicate multiples or fractions of the units. Units of various sizes are commonly formed by the use of such prefixes. The prefixes of the metric system, such as kilo and milli, represent multiplication by powers of ten. In information technology it is common to use binary prefixes, which are based on powers of two. Historically, many prefixes have been used or proposed by various sources, but only a narrow set has been recognised by standards organisations.

Answer:

[tex]Cp=0.552\frac{J}{g\°C}[/tex]

Explanation:

Hello,

In this case, the formula to compute the required heat based on the mass, specific heat and change in temperature is widely known as:

[tex]Q=mCp\Delta T[/tex]

In such a way, since we are asked to compute the specific heat, we solve for it as shown below:

[tex]Cp=\frac{Q}{m\Delta T}=\frac{1870J}{75.01g*45.2\°C} \\ \\Cp=0.552\frac{J}{g\°C}[/tex]

Best regards.

The specific heat of the metal exhibiting 45.2 [tex]\rm ^\circ C[/tex] temperature change has been 0.55 J/g.[tex]\rm ^\circ C[/tex].

The specific heat can be defined as the amount of heat required to raise the temperature of 1 gram of a substance by 1 degree Celsius.

The expression can be given as:

Q = mc[tex]\Delta[/tex]T

where, Q = heat required = 1870 J

m = mass = 75.01 g

c = specific heat capacity

[tex]\Delta[/tex]T = change in temperature = 45.2 [tex]\rm ^\circ C[/tex]

1870 J = 75.01 g [tex]\times[/tex] c [tex]\times[/tex] 45.2 [tex]\rm ^\circ C[/tex]

c = [tex]\rm \dfrac{1870}{75.01\;\times\;45.2}[/tex]

c = 0.55 J/g.[tex]\rm ^\circ C[/tex]

The specific heat of the metal exhibiting 45.2 [tex]\rm ^\circ C[/tex] temperature change has been 0.55 J/g.[tex]\rm ^\circ C[/tex].

For more information about the specific heat capacity, refer to the link:

https://brainly.com/question/13369050

Answer:

15

Explanation:

it would probably be the same number!

Answer:

Explanation:

15

Answer:

The density of a substance that has a mass of 75 g and a volume of 35 mL is 2.14 [tex]\frac{g}{mL}[/tex]

Explanation:

Density is a characteristic property of a substance that relates to the amount of mass it has per unit volume. In other words, density is the property that matter, whether solid, liquid or gas, has to compress into a given space (it measures the amount of mass in a given volume of a substance). It is calculated as the quotient between the mass of a body and the volume it occupies:

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

In this case, you know:

Replacing:

[tex]density=\frac{75 g}{35 mL}[/tex]

Solving:

[tex]density=2.14\frac{g}{mL}[/tex]

The density of a substance that has a mass of 75 g and a volume of 35 mL is 2.14 [tex]\frac{g}{mL}[/tex]

The density should be2.14 g/ml.

Given that,

Based on the above information, the calculation is as follows:

[tex]Density = mass \div volume\\\\ = 75 \div 35[/tex]

= 2.14 g/mL

Learn more: https://brainly.com/question/15959704?referrer=searchResults

Answer:

Significant Figures

Explanation:

1) Annotation category: ...

2)RULES FOR SIGNIFICANT FIGURES.

3) All non-zero numbers ARE significant. ...

4)Zeros between two non-zero digits ARE significant. ...

5)Leading zeros are NOT significant. ...

6)Trailing zeros to the right of the decimal ARE significant. ...

7)Trailing zeros in a whole number with the decimal shown ARE significant.  8) to make you happy :) hope this helps you :)

Answer:

true

Explanation:

because if you find the right answer that proves the theory to be correct.  

Answer:

Explanation:

The volume of a gas can be found by using the formula

V = n × V(dm³)

where

n is the number of miles

V is the volume

V(dm³) is the volume of 1 mole of a gas at STP which is 22.4 dm³

From the question

n = 2.56

The volume is

V = 2.56 × 22.4

We have the final answer as

Hope this helps you

Stack effect? I'm not totally sure about this...

Explanation:

Large amount of tiny particles of water droplets, dust and smoke are present on a misty day. These tiny particles in the air scatter blue colour of white light passing through it. When this scattered light reaches our eyes, the smoke appears blue.

Explanation:

Distinguish chemical substances from mixtures

Key Points

Matter can be broken down into two categories: pure substances and mixtures. Pure substances are further broken down into elements and compounds. Mixtures are physically combined structures that can be separated into their original components.

A chemical substance is composed of one type of atom or molecule.

A mixture is composed of different types of atoms or molecules that are not chemically bonded.

A heterogeneous mixture is a mixture of two or more chemical substances where the various components can be visually distinguished.

A homogeneous mixture is a type of mixture in which the composition is uniform and every part of the solution has the same properties.

Various separation techniques exist in order to separate matter, including include distillation, filtration, evaporation and chromatography. Matter can be in the same phase or in two different phases for this separation to take place.

Terms

substanceA form of matter that has constant chemical composition and characteristic properties. It is composed of one type of atom or molecule.

elementA chemical substance that is made up of a particular kind of atom and cannot be broken down or transformed by a chemical reaction.

mixtureSomething that consists of diverse, non-bonded elements or molecules.

Answer:

a pure substance made up of only one kind

Explanation:

Answer:

Explanation:

False but I could be wrong but I’m pretty sure.

Answer:

False.

Explanation:

 An ion has an imbalanced number of protons and electrons. Hope this helps! =)

Answer:

Death in the Water: How Plastic Is Poisoning Our Oceans

Liz Greene February 17, 2017

We live in a society obsessed with convenience, and that obsession has made plastic king. Though humankind has greatly benefited from plastic, the environmental costs of this reigning polymer may bring about our downfall. Traveling from land to sea in the wind or through waterways, plastic pollution is causing extensive damage to our marine life and giving life to one of the greatest ecological disasters of our times.

Plastic has been collecting in the marine environment since plastic production began in the 1950s — in fact, each square mile of the ocean contains more than 46,000 pieces of floating plastic. Eight million metric tons of plastics make their way into the ocean each year, hitching a ride on the currents and reaching the furthest corners of our seas — even turning up in the Antarctic wilderness. Simply put, the world’s oceans are becoming a toxic soup of plastic and other debris, and all life is being negatively affected.

Unfortunately, plastic doesn’t biodegrade — though it does eventually photodegrade (i.e., break down into smaller fragments by exposure to the sun). Photodegradation of plastic continues to the molecular level, yet photodegraded plastic remains a polymer. No matter how minute the pieces, they will always be plastic. Unlike naturally based paper or glass, they are not absorbed into or changed by natural processes — plastic never truly goes away.

Explanation:

This is a really good article I found, hope it helps

Answer:

The question did not contain any listed options. However, starch is a common white powder that will give a color change on reacting with iodine molecules

Explanation:

Iodine is a common indicator used in the lab to detect the presence of starch or starchy substances.

Iodine molecules react with amylose in starch to form a complex with a deep blue-black coloration.

Hence, a common white powder which reacts with iodine molecules to give a blue-black color must be a substance that contains starch.

The answer is:

d) cornstarch