True or false
The atomic number of an element is always more than the mass number of that elemenT

Answer:

18.5g Na2CO3

Explanation:

Chromium (III) chloride, CrCl3, reacts with Na2CO3 as follows:

2CrCl3 + 3Na2CO3 → Cr2(CO3)3(s) + 6NaCl

Where 2 moles of CrCl3 react with 3 moles of Na2CO3 to produce 1 mole of Cr2(CO3)3 -The precipitate-

To solve this question we need to find the moles of CrCl3 added. With the chemical equation we can find the moles of Na2CO3 and its mass as follows:

Moles CrCl3:

520mL = 0.520L * (0.224mol/L) = 0.116 moles CrCl3

Moles Na2CO3:

0.116 moles CrCl3 * (3 mol Na2CO3 / 2mol CrCl3) = 0.175 moles Na2CO3

Mass Na2CO3 -Molar mass: 105.99g/mol-

0.175 moles Na2CO3 * (105.99g/mol) = 18.5g Na2CO3

Answer:

3. The mass of ethanol required is approximately 0.522869 g

The mass of ethanoic acid required is approximately 0.68156 g

4. The mass of iron (III) oxide required is approximately 285.952.189.095 tonnes

5. The mass of silver nitrate required is approximately 14.53 grams

6. The mass of copper oxide that would be needed is approximately 31.86 grams

7. a. The mass of the precipitate, Zn(OH)₂ formed is approximately 49.712 grams

b. The mass of the precipitate, Al(OH)₃ formed is approximately 13 grams

c. The mass of the precipitate, Mg(OH)₂, formed is approximately 14.579925 grams

Explanation:

3. The 1 mole of ethanol and 1 mole of ethanoic acid combines to form 1 mole of ethyl ethanoate

The number of moles of ethyl ethanoate in 1 gram of ethyl ethanoate, n = 1 g/(88.11 g/mol) = 1/88.11 moles

∴ The number of moles of ethanol = 1/88.11 moles

The number of moles of ethanoic acid = 1/88.11 moles

The mass of ethanol = (46.07 g/mol) × 1/88.11 moles = 0.522869 g

The mass of ethanoic acid in the reaction = 60.052 g/mol × 1/88.11 moles ≈ 0.68156 g

4. 1 mole of iron(III) oxide reacts with 1 mole of CO₂ to produce 1 mole of iron

The number of moles in 100 tonnes of iron= 100000000/55.845 = 1790670.60614 moles

The mass of iron (III) oxide required = 159.69 × 1790670.60614 = 285952189.095 g ≈ 285.952.189.095 tonnes

5. The number of moles of NaCl in 5 grams of NaCl = 5 g/58.44 g/mol = 0.0855578371 moles

The mass of silver nitrate required, m = 169.87 g/mol × 0.0855578371 moles ≈ 14.53 grams

6. The number of moles of CuSO₄·5H₂O in 100 g of CuSO₄·5H₂O = 100 g/(249.69 g/mol) ≈ 0.4005 moles

The mass of copper oxide required, m = 79.545 g/mol × 0.4005 moles ≈ 31.86 grams

7. a. The number of moles of NaOH in the reaction = 20 g/(39.997 g/mol) ≈ 0.5 moles

2 moles of NaOH produces 1 mole of Zn(OH)₂

0.5 moles of NaOH will produce 0.5 mole of Zn(OH)₂

The mass of 0.5 mole of Zn(OH)₂ = 0.5 mole × 99.424 g/mol = 49.712 grams

The mass of the precipitate, Zn(OH)₂ formed = 49.712 grams

b. 6 moles of NaOH produces 2 moles Al(OH)₃

20 g, or 0.5 mole of NaOH will produce (1/6) mole of Al(OH)₃

The mass of the precipitate, Al(OH)₃ formed, m = 78 g/mol×(1/6) moles = 13 grams

c. 2 moles of NaOH produces 1 mole of Mg(OH)₂, therefore;

20 g or 0.5 moles of NaOH formed (1/4) mole of Mg(OH)₂

The mass of the precipitate, Mg(OH)₂, formed, m = 58.3197 g/mol × (1/4) moles = 14.579925 grams

Answer:

Explanation:

i will show in details how 2 do the 1st Q n u can do the rest by following the way how it is done

3. given C^2H^5OH + CH^3CO^2H → CH^3CO^2C^2H^5 + H^2O

molar ratio of ethanol, ethanoic acid and ethyl ethanoate is 1 : 1 : 1

so mass = no. of moles * molecular mass

for same no. of moles, mass / molecular mass is the same

molecular mass of CH^3CO^2C^2H^5 = 12+1*3+12+16*2+12*2+5*1 = 88

molecular mass of C^2H^5OH = 12*2+1*5+16+1 = 46

molecular mass of CH^3CO^2H = 12+1*3+12+16*2+1 = 60

1 g of ethyl ethanoate = 1/88 mole

it requires 1/88*46 = 0.5227 g of ethanol; and

1/88*60 = 0.6818 g of ethanoic acid

to react together to form 1 g of ethyl ethanoate

Answer:

He should ask an adult if they know what the solution is. if they dont, put it back and find a different cleaning solution to use

Answer:

See explanation

Explanation:

The structure of ethylene is shown in the image attached. The two carbon atoms have a double covalent bond between them.

The two carbon atoms are sp2 hybridized. The bond between them is a covalent bond, there is one pi bond and one sigma bond between the carbon atoms. Between carbon and hydrogen, there are covalent bonds also. The covalent bonds are sigma bonds.

The pi bonds between carbon atoms is weaker than the sigma bonds between the carbon atoms. This is because, the side-by-side overlap the p orbitals in a pi bond is less effective than the end-to-end overlap of a sigma bond.

Answer:

False

Explanation:

No, the mass of an electron is not equal to the mass of a neutron. Mass of neutron is greater than the mass of an electron.

Answer: Here are the answers

Explanation:

7a) Calcium Chloride +water+carbon dioxide

b)Calcium Oxide +Carbon dioxide

8a) zinc + carbon monoxide

b) Aluminum + Carbon dioxide

c) Lead + carbon dioxide

Answer:

CH2O

Explanation:

According to this question:

C = 2.04g

H = 0.34g

O = 2.73g

First, we divide the mass value of each element by its atomic mass to convert to moles.

C = 2.04g ÷ 12 = 0.17mol

H = 0.34g ÷ 1 = 0.34mol

O = 2.73g ÷ 16 = 0.17mol

Next, we divide by the smallest mole value (0.17):

C = 0.17mol = 0.17 = 1

H = 0.34mol ÷ 0.17 = 2

O = 0.17mol ÷ 0.17 = 1

The whole number ratio of C,H,O is 1:2:1, hence, the empirical formula is CH2O.

Answer:

Swimming pool is an example of solution

Explanation:

It has water (solvent) and dissolve ion (solute)

Answer:

it is a solution

Explanation:

the combining of (water and Cl and other pool chemicals) make it a solution.

Answer:

The combination of ions most likely to produce a precipitate is a group of answer choices:

lead nitrate soluble in water

Mg2+ and C2H3O2-.

Fe3+ and OH-.

Li+ and PO43-.

Pb2+ and NO3-.

NH4+ and SO42-.

Explanation:

Among the given options,

magnesium acetate, lithium phosphate, lead nitrate, ammonium sulfate are soluble in water.

The only one which is insoluble in water is [tex]Fe^3+[/tex] and [tex]OH^-[/tex] combination.

[tex]Fe(OH)_3[/tex] is insoluble in water. It forms a precipitate.

Answer:

the answer would be d. usually dull in appearance

Explanation:

because brittle bendable and poor conductor of heat and electricity are all for the non-metals

Answer:

C !!

Explanation:

hope this helps! usually people classify metals based on if they can conduct heat or electricity

Answer:

See explanation

Explanation:

According to Fajan's rules, the degree of covalent character of a bond depends on the relative polarizing power of ions.

Generally, ions become more polarizing when they are small and highly charged. Large negative ions are more polarizable than small ones.

A very small positive charge concentrated on a small area such as in Fe^2+ makes the ion highly polarizing. Also, a large negative ion such as S^2- is highly polarizable.

As a result of these FeS has considerable covalent character hence we can not simply write the formula of the ionic compound that forms between Fe and S?

Answer:

3 Protons, 2 Neutrons, & 3 Electrons. Is the charge of this atom positive, negative, or neutral?

Explanation:

Put these atoms in order from most negative overall charge to least negative

overall charge.

11 Atom X: 104 protons, 102 electrons

11 Atom B: 24 protons, 18 electrons

1 Atom Q: 15 protons, 16 electrons

11. Atom P: 7 protons, 10 electrons

The international system of units is known as SI and is a metric system. Mostly used as a system of measurement. It is used in science, technology, and nearly in every part of the country. The system includes coherent units known as derived units.

Hence the option B is correct.

Learn more about the frequently used in chemical calculations.

brainly.com/question/26120603.

Answer:

What period is the atom in?

1.

What group is the atom in?

What is the name of this atom?

What other atom would have similar

properties to the atom?

Will this atom conduct electricity well

Explanation:

How many of each kind of atom is in one molecule of water? 1 hydrogen atom and 2 oxygen atoms 1 hydrogen atom and 1 oxygen atom 2 hydrogen atoms and 1 oxygen atom 2 hydrogen

and 2 oxygen atoms

Answer:

An atom of an element that exhibits typical metallic properties, being typically shiny, with high electrical and thermal conductivity. ... A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polymeric sulfur nitride.

Answer:

0,005

Explanation:

number of moles=mass/molecular mass

therefore it's going to be 0,20g over 40g/mol

which is 0,20g/40g/mol... grams and grams will cancel making the answer 0,005moles

Metal containers are not used for storing acid because most of the time acid reacts with almost every metal and produces salts or oxides which alters the acid characteristics making it useless....

Answer:

highly concentrated solution of acid

Answer:

Your question was explained in my chemistry book so I just shared the picture

Hope that helps

Answer:

The frequency of a wave that has a wavelength of 28 m is 1.07*10⁷ Hz.

Explanation:

Wavelength is the minimum distance between two successive points on the wave that are in the same state of vibration. It is expressed in units of length (m).

Frequency is the number of vibrations that occur in a unit of time. Its unit is s⁻¹ or hertz (Hz).

The propagation speed is the speed with which the wave propagates in the medium, that is, it is the magnitude that measures the speed at which the wave's disturbance propagates along its displacement. Relate the wavelength (λ) and the frequency (f) inversely proportional using the following equation:

v = f * λ.

Being:

Replacing:

2.998*10⁸ m/s= f* 28 m

Solving:

[tex]f=\frac{2.998*10^{8}m/s }{28m}[/tex]

f= 1.07*10⁷ Hz

The frequency of a wave that has a wavelength of 28 m is 1.07*10⁷ Hz.

Answer:its B

Explanation:

i have done this before! and i got 100 so i hope you got all the other questions right!

The table shows four reactions. The reaction That is an example of combustion of an organic substance is C₂H₄ + H₂ → C₂H₆. The correct option is b) 2.

Combustion reactions are those reactions in which the reactant reacts with oxygen and produces heat and light. An example is the burning of wood, it happens in the presence of oxygen.

Organic compounds are those compounds that are made by carbons. They are made by carbon-carbon or carbon-hydrogen bonds. They are naturally present in nature.

C₂H₄ + H₂ → C₂H₆

The equation above shows the reaction between methane and hydrogen, which is forming ethane in the presence of oxygen.

Thus, the correct option is b) 2. C₂H₄ + H₂ → C₂H₆.

To learn more about combustion reactions, refer to the link:

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#SPJ5

Answer:

Synthetic sponges are made of three basic ingredients: cellulose derived from wood pulp, sodium sulphate, and hemp fiber. Other materials needed are chemical softeners, which break the cellulose down into the proper consistency, bleach, and dye.

Explanation:

IDK, BUT HOPE IT HELPS?

Viruses are known as obligatory parasites as they only become active and multiply when inside a host. Viruses are inactive when they are outside.

Explanation:

2C +O2 = 2CO

this will be the answer

Answer:

Brownian moment means zig-Zag motion of particals Randomly anywhere in the free space or in fluids

Answer: A mass of 124457.96 g ammonia is produced by reacting a 450 L sample of nitrogen gas at a temperature of 450 K and a pressure of 300 atm.

Explanation:

Given: Volume = 450 L

Temperature = 450 K

Pressure = 300 atm

Using ideal gas equation, moles of nitrogen are calculated as follows.

PV = nRT

where,

P = pressure

V = volume

n = no. of moles

R = gas constant = 0.0821 L atm/mol K

T = tempertaure

Substitute values into the above formula as follows.

[tex]PV = nRT\\300 atm \times 450 L = n \times 0.0821 L atm/mol K \times 450 K\\n = \frac{135000}{36.945}\\= 3654.08 mol[/tex]

According to the given equation, 1 mole of nitrogen forms 2 moles of ammonia. So, moles of ammonia formed by 3654.08 moles of nitrogen is as follows.

[tex]2 \times 3654.08 mol\\= 7308.16 mol[/tex]

As moles is the mass of substance divided by its molar mass. So, mass of ammonia (molar mass = 17.03 g/mol) is as follows.

[tex]Moles = \frac{mass}{molar mass}\\7308.16 = \frac{mass}{17.03 g/mol}\\mass = 124457.96 g[/tex]

Thus, we can conclude that a mass of 124457.96 g ammonia is produced by reacting a 450 L sample of nitrogen gas at a temperature of 450 K and a pressure of 300 atm.

Answer:

C. x⁴ + 6·x³ - 12·x  - 72

Explanation:

The given functions are;

[tex]f(x) =\sqrt{x^2 + 12 \cdot x + 36}[/tex]

g(x) = x³ -12

We have that [tex]f(x) =\sqrt{x^2 + 12 \cdot x + 36}[/tex] = [tex]f(x) =\sqrt{(x + 6)^2}[/tex] =  (x + 6)

Therefore;

f(x)·g(x) = [tex]\sqrt{x^2 + 12 \cdot x + 36}[/tex] × (x³ - 12) = (x + 6) × (x³ - 12)

(x + 6) × (x³ - 12) = x⁴ - 12·x + 6·x³ - 72 = x⁴ + 6·x³ - 12·x  - 72

∴ f(x)·g(x) = [tex]\sqrt{x^2 + 12 \cdot x + 36}[/tex] × (x³ - 12) = x⁴ + 6·x³ - 12·x  - 72

Answer:

18,9g de hexano son necesarios

Explanation:

Basados en la ley de Raoult, la presión de vapor ejercida por una solución es:

P = P°*Xsolvente

Donde P es la presión de la solución deseada = 700mmHg, P° la presión de vapor de vapor del benceno = 1atm = 760mmHg y X es la fracción molar del solvente (Benceno).

Reemplazando:

700mm Hg = 760mmHg * X(Benceno)

0.9211 = X(Benceno)

La fracción molar de benceno se define como:

X = Moles benceno / Moles benceno + Moles hexano

Moles benceno -Masa molar: 78g/mol-

200g * (1mol/78g) = 2.5641 moles benceno

X = Moles benceno / Moles benceno + Moles hexano

0.9211 = 2.5641 moles benceno / 2.5641 moles benceno + Moles hexano

0.9211moles Hexano + 2.3618 = 2.5641

0.9211*Moles Hexano = 0.2023

Moles hexano = 0.2023/0.9211 = 0.2196 moles hexano.

Masa Hexano -Masa molar: 86g/mol-

0.2196 moles hexano * (86g/mol) =

La cantidad de hexano (C6H14) que se debe agregar a 200 g de benceno para permitir que la presión de vapor se convierta en 700 mm de Hg sería:

18.9 g

Usando la ley de Raoult, la presión de vapor que libera una solución se encuentra por:

P = P ° × X disolvente  

Donde (P) denota la presión de la solución deseada

P ° denota la presión de vapor del benceno y

X denota la fracción molar del disolvente (benceno).

En el caso dado,

(P) = 700 mmHg,

P° = 1atm = 760mmHg

Fracción molar de benceno = 0,9211           (∵ 700/760)

La fracción molar de benceno (X)  = Moles de benceno/Moles de benceno + Moles de hexano

Moles de benceno - Masa molar: 78g / mol -  200 g × (1 mol / 78 g)

= 2.5641 moles de benceno

X = Moles de benceno/Moles de benceno + Moles de hexano

0.9211 = 2.5641 moles Benceno/2.5641 moles Benceno + Moles de Hexano

⇒ 0,9211 × moles de Hexano + 2,3618 = 2,5641    

⇒ 0.9211 × moles de Hexano = 0.2023

∵ Moles de Hexano = 0.2023/0.9211

[tex]= 0.2196 moles[/tex]

[tex]Hexane mass - Molar mass = 86g/mol - 0.2196 mole hexane[/tex] × [tex](86g/mole)[/tex]

[tex]= 18.9g[/tex]

Por tanto, 18,9 g es la respuesta correcta.

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