Radiation that travels across distances in
the form of waves is which of the
following?
A. matter
B. a cell
C. a vacuum
D. energy

Answer:

205mL of 0.140M KF solution

Explanation:

pH = 2.70 solution.

It is possible to obtain the pH of the buffer of HF-KF using the H-H equation:

pH = pKa + log [KF] / [HF]

Where pH is desire pH = 2.70

pKa is pKa of HF = 3.17

[KF] could be taken as moles of KF

And [HF] moles of HF: 400.0mL = 0.4L * (0.212mol/L) = 0.0848 moles of HF

Replacing:

2.70 = 3.17 + log [KF] / [0.0848 moles HF]

-0.47 = log [KF] / [0.0848 moles HF]

0.3388 = [KF] / [0.0848 moles HF]

[KF] = 0.02873 moles of KF must be added.

In mL using concentration of KF (0.140M):

0.02873 moles KF * (1L / 0.140 mol) = 0.205L =

Answer:elements cannot be split into two

Explanation:elements are pure substances which cannot be split into two by chemical means

Answer:

5.00 moles O₂

General Formulas and Concepts:

Chemistry - Atomic Structure

Explanation:

Step 1: Define

3.01 × 10²⁴ molecules O₂

Step 2: Convert

[tex]3.01 \cdot 10^{24} \ mc \ O_2(\frac{1 \ mol \ O_2}{6.022 \cdot 10^{23} \ mc \ O_2} )[/tex] = 4.99834 moles O₂

Step 3: Check

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

4.99834 moles O₂ ≈ 5.00 moles O₂

Graphite is sometimes used to reduce the friction between two surfaces that are rubbing together. Therefore, this happen because of weak covalent bond.

Graphite is among the most prevalent carbon allotropes. It is also the stable allotrope for carbon, and as such, it is employed in electrochemistry to define the heat of synthesis of carbon compounds. With a hardness of 2.09-2.23 g/cm3, graphite is an excellent conductor of electricity and heat.

Graphite is a large covalent structure in which each carbon atom is covalently linked to three other carbon atoms. Graphite is sometimes used to reduce the friction between two surfaces that are rubbing together. This happen because of weak covalent bond.

Therefore, graphite is sometimes used to reduce the friction between two surfaces that are rubbing together. This happen because of weak covalent bond.

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Answer:

True

Explanation:

Mixtures are substances with indefinite composition. They consist of two or more elements  and or compounds in any proportion by mass.

From these properties we can clearly identify that to separate mixtures, we use the differences in the chemical properties of the constituents of the mixtures.

because there ice is melting....... is your answer

Answer:

D

Explanation:

My favorite pancake recipe

2 cups all purpose | plain flour, (290 g | 10 oz)

1/4 cup granulated sugar or sweetener, (60g | 2 oz)

4 teaspoons baking powder

1/4 teaspoon baking soda

1/2 teaspoon salt

1 3/4 cups milk, (440ml)

1/4 cup butter, (60g | 2 oz)

2 teaspoons pure vanilla extract

1 large egg

Combine everything in a bowl (separate wet and dry) and cook at medium low heat until it is brown and there are bubbles on top. Then serve with syrup. Good luck!!!

Answer:

Fair test.

PLS GIVE BRAINLIEST

Answer:

Question are not clear

Answer:

0.075 mol/dm^3

Explanation:

Answer:

a. Boron trifluoride

b. Propane

c. Dinitrogen pentoxide

d. Carbon Dioxide

e. Silicon Octafluroride?

Explanation:

Glad to help :)

Answer:

V₁   = 208.3 mL

Explanation:

Given data:

Initial molarity of HCl  = 6.0 M

Final volume = 500 mL

Final molarity = 2.5 M

Volume of initial solution required = ?

Solution:

Formula:

M₁V₁   =  M₂V₂

Now we will put the values in formula.

6.0 M × V₁   = 2.5 M ×500 mL

6.0 M × V₁   = 1250 M.mL

V₁   = 1250 M.mL / 6.0 M

V₁   = 208.3 mL

Answer:

B.

Explanation:

i think its B

The number of oxygen atoms = 3

Mass = 24 g

The formula of a compound shows the composition of the constituent elements

CaCO₃ is composed of 3 types of elements, namely Ca, C and O

The amounts of each of these elements in the compound CaCO₃:

So the number of oxygen atoms = 3

mass of Oxygen :

[tex]\tt mass~O=\dfrac{3\times Ar~O}{MW~CaCO_3}\times mass~CaCO_3\\\\mass~O=\dfrac{3\times 16}{100}\times 50=24~g[/tex]

Answer:

A

Explanation:

its A

facts o.o

Nuclear power plants pollute the environment and causes cancer in populations that use nuclear energy instead of traditional electricity. Hence option A is correct.

Nuclear power plant is defined as a particular kind of power plant that produces electricity by nuclear fission. Nuclear power plants use the heat generated by nuclear fission to transform water into steam in a controlled environment, which then powers generators to produce electricity.  Low-enriched uranium fuel is used in nuclear power plants to generate electricity through a process known as fission, which involves breaking uranium atoms in a nuclear reactor.

A clean energy source with no emissions is nuclear. It produces energy by fission, which is the splitting of uranium atoms to release energy. Without the toxic consequences that come from burning fossil fuels, electricity is produced using the heat from fission to produce steam, which turns a turbine.

Thus, nuclear power plants pollute the environment and causes cancer in populations that use nuclear energy instead of traditional electricity. Hence option A is correct.

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Explanation:

Given parameters:

Number of moles of Cu  = 0.696mol

Volume of HNO₃  = 146mL

Concentration of HNO₃  = 5.5M

Unknown:

Will Cu react completely = ?

Limiting reagent  = ?

Remaining mass of the compound  = ?

Solution:

The equation of the reaction is given as;

             Cu + 4HNO₃  →  Cu(NO₃)₂  + 2H₂O  + 2NO₂

Let us find the number of moles of HNO₃ ;

  Number of moles  = concentration x volume

  Number of moles  = 5.5 x 146 x 10⁻³L = 0.803mol

From the balanced reaction equation;

      1 mole of Cu reacted with 4 mole of HNO₃

       0.696 mole of Cu will require 4 x 0.696  = 2.784mole of HNO₃

So, the limiting reactant is HNO₃ because it is in short supply.

Cu will completely react

Mass of the remaining compound we need;

       mass  = number of moles x molar mass

  Number of moles = 2.784  - 0.803  = 1.981mole

So, mass  = 1.981 x (1 + 14 + 3(16))  = 124.81g of HNO₃ is required to make the reaction complete.

The limiting reagent is HNO3 and the remaining compound in mass is 25.1 grams of Cu.

The reaction taking place in the given case is,

Based on the given information,

• The moles of Cu given is 0.696 moles.  

• The volume of HNO3 given is 146 ml and the molarity of HNO3 is 5.5 M.

Now the moles of HNO3 can be determined as,

[tex]Moles = \frac{M1V1}{1000} \\Moles = \frac{5.5M*146 ml}{1000} \\Moles = 0.803 moles[/tex]

• In order to find the limiting reagent, there is a need to divide moles by their stoichiometric coefficient, that is,  

Cu = 0.696/3 = 0.232 moles and HNO3 = 0.803/8 = 0.100 moles

• As the moles of HNO3 is present in less amount, therefore, HNO3 will be the limiting reagent.  

Now the remaining copper left in the reaction will be,

[tex]= 0.696-\frac{3}{8} *0.803\\= 0.696-0.300\\= 0.396 moles[/tex]

Now the mass of remaining copper will be = Moles * Molecular mass of Cu

[tex]Mass = 0.396 moles * 63.5 g/mol\\Mass = 25.1 g[/tex]

Thus, the mass of remaining compound is 25.1 grams and the limiting reagent is HNO3.

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Answer:

the lithosphere is broken into sections called plates.

Answer:

The lithosphere is broken into sections called plates.

Explanation:

edge2020

Answer:

72.6% Error

Explanation:

% error = [tex]\frac{Real-Measured}{Real} * 100[/tex]

[tex]\frac{58.44-16}{58.44} *100= 72.6[/tex]

58.44 is the weight of NaCl

Answer:

7

Explanation:

Answer:

M = 17 M

Explanation:

Given data:

Mass of sodium hydroxide = 678.57 g

Volume of solution = 1.00 L

Molarity  of solution = ?

Solution:

Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.

Formula:

Molarity = number of moles of solute / L of solution

Number of moles of sodium hydroxide:

Number of moles = mass/molar mass

Number of moles = 678.57 g /40 g/mol

Number of moles = 17 mol

Molarity:

M =  17 mol/1.00 L

M = 17 mol/L

M = 17 M

Answer:

[tex]\boxed {\boxed {\sf882 \ Joules}}[/tex]

Explanation:

Potential energy can be found by multiplying the mass by the height by the gravitational acceleration.

[tex]PE=mgh[/tex]

The mass is 45 kilograms. The height is 2 meters. The gravitational acceleration on Earth is 9.8 meters per seconds squared.

[tex]m=45 \ kg \\h= 2 \ m \\g=9.8 \ m/s^2[/tex]

Substitute the values into the formula.

[tex]PE=45 \ kg * 2 \ m * 9.8 m/s^2[/tex]

Multiply.

[tex]PE=441 kg*m/s^2*2 \ m[/tex]

[tex]PE= 882 \ kg *m/s^2 *m[/tex]

1 kg*m/s^² is equal to 1 Newton (N). Substitute N in for kg*m/s²

[tex]PE=882 \ N*m[/tex]

1 Newton meter (N*m) is equal to 1 Joule (J). Our current answer is equivalent to 882 Joules.

[tex]PE= 882 \ J[/tex]

The sled's potential energy is 882 Joules.

Answer:

882 J

Explanation:

Answer:

1.70 L

Explanation:

From the question given above, the following data were obtained:

Pressure (P) = constant = 1.2 atm

Initial volume (V1) = 1.25 L

Initial temperature (T1) = 293 K

Final temperature (T2) = 398 K

Final volume (V2) =?

Since the pressure is constant, the gas is obeying Charles' law. Thus, we can obtain the new volume (V2) of the gas by applying the Charles' equation as shown below:

V1/T1 = V2/T2

1.25 / 293 = V2 /398

Cross multiply

293 × V2 = 1.25 × 398

293 × V2 = 497.5

Divide both side by 293

V2 = 497.5 / 293

V2 = 1.70 L

Therefore, the new volume of the gas is 1.70 L.

Answer:a compound

Explanation:

Answer:

Conductor

Explanation:

What we call “pencil lead” is actually a substance called graphite, which consists of many stacked sheets of carbon atoms. Like a metal, graphite is conductive and therefore can act like a wire on paper to create the circuit.

The empirical formula : C₁₂H₁₇N₂O₄P

The empirical formula is the smallest comparison of atoms of compound =mole ratio of the components

The principle of determining empirical formula

[tex]\tt \dfrac{50.7}{12}=4.225[/tex]

[tex]\tt \dfrac{6.03}{1}=6.03[/tex]

[tex]\tt \dfrac{9.86}{14}=0.704[/tex]

[tex]\tt \dfrac{22.51}{16}=1.407[/tex]

[tex]\tt \dfrac{10.9}{31}=0.352[/tex]

Divide by the smallest mole ratio(0.352)

C : H : N : O : P

[tex]\tt C\rightarrow \dfrac{4.225}{0.352}=12[/tex]

[tex]\tt H\rightarrow \dfrac{6.03}{0.352}=17[/tex]

[tex]\tt N\rightarrow \dfrac{0.704}{0.352}=2[/tex]

[tex]\tt O\rightarrow \dfrac{1.407}{0.352}=4[/tex]

[tex]\tt P\rightarrow \dfrac{0.352}{0.352}=1[/tex]

Answer:

Explanation:

no of moles of C2H6=10/30=0.33

complete combustion of 2 moles of ethane produce 4 moles of CO2 therefore 0.33 moles of C2H6 produced 0.66 moles of CO2

now moles =given mass/molar mass

mass= moles*molar mass

mass of CO2=0.67*44=29.48 g

Percent by mass : 4.10⁺³%

The concentration of a solution can be expressed in units such as molarity, normality, mass percent, volume percent etc.

[tex]\tt \%mass=\dfrac{mass~solute}{mass~solution}\times 100\%[/tex]

mass solute= mass of NaOH  

mass of NaOH :

[tex]\tt 0.001~mol/L\times 1~L\times 40~g/mol=0.04~g[/tex]

mass solution = 1000 g

% mass :

[tex]\tt \dfrac{0.04}{1000}\times 100=4.10^{-3}\%[/tex]

The percent by mass concentration of NaOH in the given solution is approximately 0.004%.

To calculate the percent by mass concentration of NaOH, we must find the mass of NaOH in solution.

First, we determine how many moles of NaOH are present in the solution:

Molarity (M) is calculated as moles of solute per liter of solution.

1 L = 0.001 M = mole of NaOH

We rearrange the equation to find that one mole of NaOH is equal to 0.001 moles.

Mass of NaOH = moles of NaOH * molar mass of NaOH

Mass of NaOH = 0.001 mol * 40.00 g/mol

Mass of NaOH = 0.04 g

The mass of the solution is 1000 g which is given in the question.

Percent by mass concentration of NaOH = (mass of NaOH / mass of solution) * 100%

Percent by mass concentration of NaOH = (0.04 g / 1000 g) * 100%

Percent by mass concentration of NaOH = 0.004%

Hence, the percent by mass concentration of NaOH in the given solution is approximately 0.004%.

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Answer:

Nonmetals form negative ions (anions). A nitrogen atom must gain three electrons to have the same number of electrons as an atom of the following noble gas, neon. Thus, a nitrogen atom will form an anion with three more electrons than protons and a charge of 3−.

Explanation:

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