explain why an indicator is used in titration

Answer:

Graphitic carbon nitride (g-C3N4) is a rising two-dimensional material possessing intrinsic semiconducting property with unique geometric configuration featuring superimposed heterocyclic sp2 carbon and nitrogen network, nonplanar layer chain structure, and alternating buckling. The inherent porous structure of heptazine-based g-C3N4 features electron-rich sp2 nitrogen, which can be exploited as a stable transition metal coordination site. Multiple metal-functionalized g-C3N4 systems have been reported for versatile applications, but local coordination as well as its electronic structure variation upon incoming metal species is not well understood. Here we present detailed bond coordination of divalent iron (Fe2+) through micropore sites of graphitic carbon nitride and provide both experimental and computational evidence supporting the aforementioned proposition.

Answer:

Explanation:

V1/T1 =V2/T2    at constnant pressure

Answer:

c

Explanation:

Answer:

im pretty sure they heat up

Explanation:

as they use energy to go from solid to liquid to gas, they need heat to do so as they have a melting and boiling point

Answer:

Four main processes erode the destructive waves; hydraulic action, compression, abrasion and attrition. Hydraulic Action is the sheer force of water crashing off the coastline causing the material to dislodge and be carried away by the sea.

Answer:

a

Explanation:

Answer:

The correct option is;

4 percent ionic, 96 percent covalent, 222 pm

Explanation:

The parameters given are;

Phosphorus:

Atomic radius = 109 pm

Covalent radius = 106 pm

Ionic radius = 212 pm

Electronegativity of phosphorus = 2.19  

Selenium:

Atomic radius = 122 pm

Covalent radius = 116 pm

Ionic radius = 198 pm

Electronegativity of selenium= 2.55  

The percentage ionic character of the chemical bond between phosphorus and selenium is given by the relation;

Using Pauling's alternative electronegativity difference method, we have;

[tex]\% \, Ionic \ Character = \left [18\times (\bigtriangleup E.N.)^{1.4} \right ] \%[/tex]

Where:

Δ E.N. = Change in electronegativity = 2.55 - 2.19 = 0.36

Therefore;

[tex]\% \, Ionic \ Character = \left [18\times (0.36)^{1.4} \right ] \% = 4.3 \%[/tex]

Hence the percentage ionic character = 4.3% ≈ 4%

the percentage covalent character = (100 - 4.3)% = 95.7% ≈ 96%

The bond length for the covalent bond is found adding the covalent radii of both atoms as follows;

The bond length for the covalent bond = 106 pm + 116 pm = 222 pm.

The correct option is therefore, 4 percent ionic, 96 percent covalent, 222 pm.

Answer:

Independent: whether or not there was fertilizer in water

Dependent: height of plants

Explanation:

In an experiment, there is an independent and a dependent variable. The independent variable is what is changed in the experiment. The dependent variable is what is measured.

In this experiment, 10 tomato plants are given fertilizer in the water, while 10 other tomato plants are given regular water. Everything else is kept constant, and the heights are measured at the end of the week.

The independent variable is what is being changed. In this experiment, the only thing being manipulated is the fertilizer. One group of the plants is given fertilizer, while the other is not. Therefore, the independent variable is whether or not there was fertilizer in the water.

The dependent variable is what is being measured. In this experiment, the thing that is being measured is the height of the plants. Therefore, the dependent variable is the height of the plants.

Answer:

47

Explanation:

Silver (Ag), chemical element, a white lustrous metal valued for its decorative beauty and electrical conductivity. Silver is located in Group 11 (Ib) and Period 5 of the periodic table

The atomic number of silver is 47.

That also means that silver has 47 electrons and 47 protons.

The atomic mass of silver is 108u.

107 - 47 = 60

Silver has 60 neutrons.

Answer: Thus the yield of uranium from 2.50 kg [tex]U_3O_8[/tex] is 2.12 kg

Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number [tex](6.023\times 10^{23})[/tex] of particles.

To calculate the number of moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{molar mass}}[/tex]

moles of [tex]U_3O_8=\frac{2.50\times 1000g}{842g/mol}=2.97mol[/tex]    (1kg=1000g)

As 1 mole of [tex]U_3O_8[/tex] contains = 3 moles of U

2.97 mole of [tex]U_3O_8[/tex] contains = [tex]\frac{3}{1}\times 2.97=8.91moles[/tex] moles of U

Mass of Uranium=[tex]moles\times {\text {Molar mass}}=8.91mol\times 238g/mol=2120g=2.12kg[/tex]  

 ( 1kg=1000g)

Thus the yield of uranium from 2.50 kg [tex]U_3O_8[/tex] is 2.12 kg

Answer:

147.222

Explanation:

It's a simple conversion.

12,194 L is the answer!

Explanation:

Water has the maximum density at the temperature of 4°Celsius. So, it expands at temperatures higher or lower than 4°C, knowing that at the temperature of -25°C the water can't have a lower volume than the one at 15°C.

Answer:

12, 194 L

That's your answer!!!

Answer:

Pulmonary circulation moves blood between the heart and the lungs. The oxygenated blood then flows back to the heart. Systemic circulation moves blood between the heart and the rest of the body. It sends oxygenated blood out to cells and returns deoxygenated blood to the heart

Explanation:

Answer:

2H + O -------> H2O

and hydrogen react with oxygen so it is oxide of hydrogen

like iron react with Oxygen and give

iron oxide

Explanation:

after passing electric current in the water the two gases will get seperated and on bringing the matchstick close to hydrogen it will burn with a pop sound

Answer:

B. CH₅N

Explanation:

The combustion reaction of a compound CₐHₓNₙ with O₂ is:

CₐHₓNₙ + O₂ → a CO₂ + X/2 H₂O + n NO₂

Where 1 mole of CₐHₓNₙ with an excess of O₂ produce a moles of CO₂, X/2 moles of H₂O and n moles of NO₂

Thus, you need to convert the mass of CO₂ and H₂O to moles to find the C:H ratio and determine a possible empirical formula thus:

Moles CO₂ (Molar mass 44g/mol):

44g ₓ (1mol / 44g) = 1 mole CO₂ = 1 mole C

Mole of H₂O (Molar mass 18g/mol):

45g ₓ (1 mol / 18g) = 2.5 moles H₂O = 5 moles H

Thus, in the compound you have 5 moles of H per mole of C, and a possible empirical formula is:

The only structure that meet this C:H ratio

The most likely empirical formula for the one that exemplifies a specimen of the compound containing the element C, H, and N which are completely combusted in oxygen to generate 44g Co2, 45g of H2O, and a little NO2 would be:

B). CH₅N

The reaction of combustion taking place in the compound CₐHₓNₙ using [tex]O_{2}[/tex] (oxygen) would be:

[tex]C_{a} H_{x} N_{n} + O_{2}[/tex]  → [tex]aCO_{2} + X/2 H_{2}O + nNO_{2}[/tex]

In this reaction, 1 mole belonging to [tex]C_{a} H_{x} N_{a}[/tex] having additional [tex]O_{2}[/tex] (oxygen) leads to generating '[tex]a[/tex]' moles of [tex]CO_{2}[/tex] (Carbon dioxide), [tex]X/2[/tex] number of moles of [tex]H_{2}O[/tex](Hydrogen), and n amount of moles of Nitrogen([tex]N[/tex]).

Therefore, it will be required to transform the mass of [tex]CO_{2}[/tex] and [tex]H_{2}O[/tex]  in the form of moles to deduce the ratio C:H to look for the likely empirical formula.

 [tex]CO_{2}[/tex] Moles                                                       (∵ Molar mass [tex]= 44g/mol)[/tex]

= [tex]44g[/tex] × [tex](1mol/44g)[/tex]

[tex]= 1 mole[/tex] of  [tex]CO_{2}[/tex]

[tex]= 1 mole[/tex] of C

[tex]H_{2}O[/tex] Moles                                                   (∵ Molar mass =[tex]18g/mol)[/tex]

[tex]= 45g[/tex] ₓ [tex](1 mol / 18g)[/tex]                          

[tex]= 2.5 moles[/tex]  [tex]H_{2}O[/tex]

[tex]= 5[/tex] [tex]moles of H[/tex] because (H * 2)

∵ The C:H ratio is 1:5 implying that formula would include 5 H moles and 1 C mole. So, CH₅N is the correct option.

Thus, option B is the correct answer.

Learn more about 'Compound' here:

brainly.com/question/23950635

Answer:

[tex]\large \boxed{1.615 \times 10^{25}\text{ molecules water}}[/tex]

Explanation:

You must calculate the mass of the water, convert it to moles, and then calculate the number of molecules.

1. Mass of water

[tex]\text{Mass } = \text{499.8 mL} \times \dfrac{\text{0.967 g}}{\text{1 mL}} = \text{483.3 g}[/tex]

2. Moles of water

[tex]\text{Moles of water} = \text{483.3 g water} \times \dfrac{\text{1 mol water}}{\text{18.02 g water}} = \text{26.82 mol water}[/tex]

3. Molecules of water

[tex]\text{No. of molecules} = \text{26.82 mol water} \times \dfrac{6.022 \times 10^{23}\text{ molecules water}}{\text{1 mol water}}\\\\= \mathbf{1.615 \times 10^{25}}\textbf{ molecules water}\\\text{The sample contains $\large \boxed{\mathbf{1.615 \times 10^{25}}\textbf{ molecules water}}$}[/tex]

The number of molecules of water  present in the bottle is 1.62×10²⁵ molecules.

We'll begin by calculating the mass of the water in the bottle.

Mass = Density × Volume

Mass of water = 0.967 × 499.8

Mass of water = 483.3066 g

Finally, we shall determine number of molecules of water in the bottle.

From Avogadro's hypothesis,

1 mole of water = 6.02×10²³ molecules

But,

1 mole of water = 18 g

Thus, we can say that:

18 g of water = 6.02×10²³ molecules

Therefore,

483.3066 g of water = (483.3066 × 6.02×10²³) / 18

483.3066 g of water = 1.62×10²⁵ molecules

Thus, the number of molecules of water in the bottle is 1.62×10²⁵ molecules.

Learn more about Avogadro's number:

https://brainly.com/question/8933381

Answer:

Because electronegativity of Oxygen is higher than electronegativity of Carbon.

Explanation:

The electrons in a bond between carbon and oxygen, C-O, closer to the oxygen atom than the carbon atom because electronegativity of Oxygen is higher than electronegativity of Carbon.

Answer:

The 5R's are Reuse, Reduce, Recycle, Repair and Recover.

Answer:

The total energy to break all the bonds in 1 mole of 1-propanol, C₃H₈O, is 4411 kJ/mol

Explanation:

We note that propanol, C₃H₈O is also known as 1-propanol is written as follows;

CH₃CH₂CH₂OH which gives

CH₃-CH₂-CH₂-OH

Hence, the total number of bonds are;

C-H Bonds = 3 + 2 + 2 = 7

C-O Bonds = 1

O-H Bond = 1

C-C Bonds = 2

The bond energies are as follows;

C-H Bonds = 413 kJ/mol

C-O Bonds = 358 kJ/mol

O-H Bond = 468 kJ/mol

C-C Bonds = 347 kJ/mol

Energy required to break the bonds in 1-propanol is therefore;

C-H Bonds = 413 kJ/mol × 7 = 2,891 kJ/mol

C-O Bonds = 358 kJ/mol × 1 = 358 kJ/mol

O-H Bond = 468 kJ/mol × 1 = 468 kJ/mol

C-C Bonds = 347 kJ/mol × 2 = 694 kJ/mol

The total energy to break all the bonds in 1 mole of 1-propanol = 4411 kJ/mol.

Answer:

According to the numbers 1-5;Aluminium,Mercury,Oxygen,Stainless Steel,Hydrogen gas.

Explanation:

Answer:

Explanation:

H

Answer:

The molar concentration of the final solution is 1.71 [tex]\frac{moles}{liter}[/tex]

Explanation:

Molarity is a way of expressing the concentration of solutions and indicates the number of moles of solute dissolved per liter of solution.

The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution.:

[tex]Molarity (M)=\frac{number of moles of solute}{volume}[/tex]

Molarity is expressed in units ([tex]\frac{moles}{liter}[/tex]).

Then, the number of moles of solute can be calculated as:

number of moles of solute= molarity* volume

So, in this case, the final concentration can be calculated as:

[tex]Final molarity (M)=\frac{Total number of moles of solute}{Total volume}[/tex]

where, being 65 mL=0.065 L, 125 mL=0.125 L and 190 mL=0.190 L (because 1000 mL= 1 L):

Replacing:

[tex]Final molarity (M)=\frac{0.324595 moles}{0.190 L}[/tex]

Final molarity ≅ 1.71 [tex]\frac{moles}{liter}[/tex]

The molar concentration of the final solution is 1.71 [tex]\frac{moles}{liter}[/tex]

Answer:

Galileo: "Father of Modern Science."

Aristotle: Geocentric theory." (The planests revolves around the earth.)

Torricelli: Invented the barometer. (An instrument which measures pressure.)

Copernicus: Heliocentric theory. (Aka, the planets revolves around the sun.)

Vesalius: Examined the inner workings of the human body

Newton: Developed law of universal gravitation.

Nightingale: Founded nursing profession.

Celsius: Developed metric temperature scale

I hope this helps! Thanks:)

Answer:

Some things you could do are recycle more, contribute to organizations that support saving the environment, finding alternate transportation methods such as riding a bike or walking, and finally, you could volunteer.

Answer:

C7H16 + 11O2 = 7CO2 + 8H2O

Explanation:

Start by balancing the C and H in C7H16 by adding the coefficient of 7 for CO2 because there are 7 C's in C7H16. Similarly, since there are 16 H's in C7H16, balance it by adding the coefficient of 8 to the H2O, which will result in 16 H's.

Finally, add up the O's on the right side and balance it by adding the appropriate coefficient on the O2. On the right, there are 22 O's, so balance the equation by adding the coefficient of 11 on the left for the O2.

Answer:

C. Rate = k[H2]^2[O2]

Explanation:

Rate law only cares about REACTANTS. Since, rate law can only be determined experimentally, I am assuming the given reaction mechanism is elementary reaction from which we can write the rate law.

Only H2 and O2 are part of rate law since they are reactants and also the coefficient in front of H2 goes as exponent on rate law to indicate the order of H2 in the reaction.

Rate= k [H2]^2 [O2]

According to the chemical equilibrium, the rate law for the given reaction is Rate = k[H₂]²[O₂] as  the concentration is dependent on both the reactants.

Chemical equilibrium is defined as the condition which arises during the course of a reversible chemical reaction with no net change in amount of reactants and products.A reversible chemical reaction is the one wherein the products as soon as they are formed react together to produce back the reactants.

At equilibrium, the two opposing reactions which take place take place at equal rates and there is no net change in amount of the substances which are involved in the chemical reaction.At equilibrium, the reaction is considered to be complete . Conditions which are required for equilibrium are given by quantitative formulation.

Factors which affect chemical equilibrium are change in concentration , change in pressure and temperature and presence of catalyst.

Learn more about chemical equilibrium,here:

https://brainly.com/question/4289021

#SPJ2

Answer:

The percentage yields are as follows :

a) 64.28%

b) 58.03%

c) 69.46%

d) 79.31%

Explanation:

The percentage yield is the ratio of the actual yield of a product to the expected or theoretical yield expressed as a percentage.

Percent yield = actual yield/theoretical yield x 100%

a) from the question, expected yield is 68.3 g whilst the actual yield is 43.9 g

therefore,

Percentage yield = 43.9 g/68.3 g x 100%

                             =  0.64275 x 100%

                             =  64.28%

b) From the question, expected yield is 0.0722 mol while the actual yield is 0.0419 mol. Therefore

Percentage yield = 0.0419 /0.0722 x 100%

                             = 0.58033 x 100%

                             = 58.03%

c) A limiting reactant is the reactant is is completely used in a recation to form a product. That is, it is the reactant that is not in excess.

From the equation of the reaction :

CH3COOH + CH3CH2OH --> CH3COOCH2CH3 + H2O

1 mole of ethanol reacts with 1 mole of acetic acid to give 1 mole of ethyl acetate.

From the question, ethanol is the limiting reactant because it is not in excess. Hence,

4.29 mole of ethanol should produce 4.29 mole of ethyl acetate (expected yield).

However only 2.98 mol of ethyl acetate is produced (actual yield)

Percentage yield = 2.98mol/4.29 mol x 100%

                            =  0.69463 x 100%

                            = 69.46%

d) From the question, acetic acid is in excess hence ethanol is the limiting reactant

therefore from the equation of the reaction:

1 mole of ethanol reacts with 1 mole of acetic acid to give 1 mole of ethyl acetate.

0,58 mol of ethanol should produce 0.58 mol of ethyl acetate (expected yield)

But 0.46 mol of ethyl acetae was produced (actual yield)

Percentage yield = 0.46mol /0.58 mol x 100%

                             = 0.79310 x 100%

                              = 79.31%

B is the answer ,ammonium accepts a proton and becomes ammonium ion

Answer: Energy is removed from the particles in each change, but more energy is removed in melting than in boiling because the attractions are weaker. Energy is removed from the particles in each change, but more energy is removed in boiling than in melting because the attractions are weaker. Energy is added to the particles in each change, but boiling requires more energy than melting because the attractions must be completely overcome. Energy is added to the particles in each change, but melting requires more energy than boiling because the attractions must be completely overcome.