how many moles are in a 4.2 gram gold sample

Answer:Fe(s) + Sn^2+(aq) ----> Fe^2+(aq) + Sn(s)

Explanation:

The net ionic equation involved is;

Fe(s) + Sn^2+(aq) ----> Fe^2+(aq) + Sn(s)

We must recall that iron is above tin in the electrochemical series. The implication of this is that, iron has a more negative reduction potential compared to tin.

A metal can displace metals below it in the electrochemical series from their aqeous solution. Hence, iron displaces tin from it's solution.

Answer: here is your answer

Explanation: You are visiting your Grandmother and notice that she is eating a balanced diet, taking vitamins, getting the proper amount of sleep and is not overweight. Despite her healthy lifestyle, she appears run down and tired. You realize that it's due to her lack of physical activity. Write a convincing letter to your grandma explaining the benefits of participating in regular physical activity.

Answer:

blocks 1 and 2 the rhdh huff hgfhh5

Answer:

0.328 mol/dm³

Explanation:

We have

I started this calculation from Rate's law.

Remember equilibrium constant has been given to be 60%

Our interest is Kc, that is the equilibrium constant.

Ca = 4(1-0.6)/1+(-0.5*0.6)

= 4-2.4/1-0.3

= 1.6/0.7

= 2.2857

Cb = 4x0.6/2(1+(-0.5*0.6))

= 2.4/2(0.7)

= 2.4/1.4

= 1.7143

Kc = Cb/Ca²

= 1.7143/2.2857²

= 1.7143/5.2244

= 0.328 mol/dm³

I have added an attachment showing earlier stages to the final answer

Answer:

K loses one electron to CI

Explanation:

The lewis electron dot notation shows only the chemical symbol of the element surrounded by dots to represent the valence electrons.

  We have atom of K with one valence electrons

   Cl with 7 valence electrons

For an electrostatic attraction to occur, both particles must be charged. To do this, one of the species must lose an electron, and the other gains it.

This will make both species attain a stable octet;

   Hence, K will lose 1 electron and Cl will gain the electrons.

Answer:

C: K loses one electron to CI

Explanation:

I took the test and got it correct!!

Answer:

Explanation:

From the information given :

The cis and trans isomer are in the ratio of 1:3, and the description of how the ratio of the cis- and trans-2-methylcyclohexanols from the 1H NMR spectrum can be explained as follows:

We are being told that the trans isomer's peak is 3.75 ppm (part per million). However, because the methyl group is far away from the OH group, it is less shilled than the cis isomer, which peaked at 3.05. Thus, the peak at 3.05 occurs in an area whose integration is three (3) times more than the peak at 3.75.

Answer:

The Inert Pair effect renders Pb(II) as the more stable oxidation state of lead

Explanation:

SnBr4 + PbBr2 ---> SnBr2 + PbBr4

SnBr2 + PbBr4 ---->

The Inert pair effect is mostly observed between group 15-17 in the periodic table. It leads to stability of the lower oxidation state of an element.

The reason for the Inert pair effect is that the s electrons become Inert due to poor shielding of the d and f-electrons. The Inert pair effect is a tendency of the s electrons not to participate in bonding (remain an Inert pair).

Owing to the Inert pair effect, Pb II is more stable than Pb IV

Answer:

The new pressure will be  

1000 L

, rounded to one significant figure.

Explanation:

Boyle's law states that when a gas is held at a constant temperature and mass in a closed container, the volume and pressure vary inversely. The equation to use is  

P

1

V

1

=

P

2

V

2

.

Given

V

1

=

200

mL

×

1

L

1000

mL

=

0.2 L

P

1

=

700 mmHg

V

2

=

100

mL

×

1

L

1000

mL

=

0.1 L

Unknown

P

2

Equation

P

1

V

1

=

P

2

V

2

Solution

Rearrange the equation to isolate  

P

2

and solve.

P

2

=

P

1

V

1

V

2

P

2

=

(

700

mmHg

×

0.2

L

)

0.1

L

=

1400 L

, which must be rounded to  

1000 L

because all of the measurements have only one significant figure

Explanation:

Answer: The answer is D.

Explanation:

The form of energy associated with the motion, position, or shape of an object is called mechanical energy. An object's mechanical energy is a combination of its potential energy and its kinetic energy. The basketball has both potential energy and kinetic energy.

Hope this helps!

Answer:

solute

Explanation:

Metals typically lose electrons to complete their octet in a reaction with non-metals, whereas non-metals typically acquire electrons to complete their octet. Ionic compounds are typically formed via reactions between metals and nonmetals. The given compound barium hydroxide is ionic.

Ions with the opposite charge are carefully packed together to form crystalline solids. Ionic compounds typically result from reactions between metals and non-metals. The electrostatic interaction between the positive and negative ions holds ionic solids together.

Baryta, commonly known as barium hydroxide, has the chemical formula Ba(OH)₂. It is an odorless, clear-white powder. It has a toxic disposition. It is ionic in nature, with two hydroxide ions per molecule of barium hydroxide (Ba(OH)₂ in an aqueous solution an example.

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Answer:

Chelation is a type of bonding of ions and molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate ligand and a single central atom. These ligands are called chelants, chelators, chelating agents, or sequestering agents.

Answer:

Chemical compound that react with metal ions. They can form several covalent bonds to a metal without changing its own structure.

Explanation:

There's a list of chelating agents you can find in your book probably. An application of chelating agents is to transport metal ions across the membranes.

you should also know:

Chelating agents are any compound that reacts with a metal ion to produce a metal ion.

Ligand ion molecule or functional group that binds to another chemical to make a larger complex.

They are used to detoxify poisonous metal agents by binding and converting them so the body can excrete them without further harm.

I'm not sure if this is the answer but maybe oil.

Answer:

Explanation:

Noble gas notation: [Xe] 6s2

Complete Electron Configuration: 1s22s22p63s23p63d104s24p64d105s25p66s2.

(ik kinda hard to understand but i looked it up ant it works)

Answer:

Complete Electronic Configuration:

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²

Electronic Configuration in Noble Gas Notation:

[Xe] 6s²

Answer: The answer is 5.15x10^22

Explanation:

The formula unit present in a teaspoon of salt [tex]NaCl[/tex] having a mass of about 5.0 g is [tex]5.15 \times10^{22}[/tex] formula units.

Molar mass, also known as molecular weight, is the mass of one mole of a substance. It is calculated by summing up the atomic masses of all the atoms in a molecule. The unit of molar mass is grams per mole (g/mol).

Now, to determine the number of formula units in a teaspoon of salt (NaCl), we need to use Avogadro's number and the molar mass of NaCl.

Avogadro's number [tex](N_a)[/tex] is approximately. [tex]6.022 \times10^{23}[/tex] formula units per mole.

The molar mass of [tex]NaCl[/tex] is the sum of the atomic masses of sodium (Na) and chlorine ([tex]Cl[/tex]), which are approximately 22.99 g/mol and 35.45 g/mol, respectively.

To calculate the number of formula units in 5.0 g of [tex]NaCl[/tex], we can follow these steps:

Now, calculate the number of moles of [tex]NaCl[/tex] using its molar mass:

Moles = Mass / Molar mass

Moles = [tex]5.0 g[/tex] / [tex](22.99 g/mol + 35.45 g/mol)[/tex]

Calculate the number of formula units using Avogadro's number:

Formula units = [tex]Moles \times Avogadro's number[/tex]

Let's perform the calculation:

Molar mass of [tex]NaCl[/tex]= [tex]22.99 g/mol + 35.45 g/mol = 58.44 g/mol[/tex]

Moles of [tex]NaCl[/tex] = [tex]5.0 g[/tex] / [tex]58.44 g/mol[/tex] ≈ [tex]0.0856 mol[/tex]

Formula units = [tex]0.0856 mol \times (6.022 \times 10^{23})[/tex] formula units/mol ≈ [tex]5.15 \times10^{22}[/tex]formula units.

Therefore, there are approximately [tex]5.15 \times10^{22}[/tex] formula units in a teaspoon of salt ([tex]NaCl[/tex]) having mass [tex]5.0 g[/tex].

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Answer:

The answer is 7.89

Explanation:

Mass of methane required to increase the temperature of the air in the room by 7.35 °C is 7.95 g

The volume of air in the room is first calculated:

Volume of air in the room = 4.33 m x 3.43 m x 3.03 = 45.00 m³

1 m³ = 1000 L

45.00 m³ = 45.00 m³ * 1000 L/m³

Volume of air in L = 45000 L

Number of moles of air in 45000 L of air is then determined:

1.00 moles of air occupies 22.4 L

number of moles of air in 45000 L = 45000 L * 1 mole / 22.4 L

number of moles of air = 2008.93 moles of air

Energy that is needed to heat the room by 7.35 °C is then calculated:

Quantity of energy needed = Specific heat capacity * number of moles * temperature increase

Specific heat capacity of air = 30.0 J/K/mole

Quantity of energy needed = 30.0 * 2008.93 * 7.35

Quantity of energy needed = 442969.065 J = 443.00 kJ

The amount of methane required to produce that amount of energy is then calculated:

Equation of combustion of methane : CH₄ + 2 O₂  ---> CO₂ + 2 H₂O

Enthalpy of combustion of methane = −890.3 kJ/mole

Number of moles of methane required = 443.00 kJ / 890.8 kJ/mole = 0.497 moles

Mass of 1 mole of methane = 16.0 g

mass of 0.497 moles of methane = 16.0 * 0.497 = 7.95 g

Therefore, mass of methane required to increase the temperature of the air in the room by 7.35 °C is 7.95 g

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Answer:

pH = 10.113

Explanation:

Here, we can find pOH first:

pOH = [tex]-log([OH^-])[/tex] = 3.886.

Then, we can find pH which is 14 - pOH. We then get the answer above.

Then, we can find pH which is 14 - pOH. We then get the answer above.

The pH of acid is between 0-7 on pH scale while for base pH range is from 7-14. Thus the pH of 1.3×10⁻⁴  M  bleach solution is 10.62.

pH is a measurement of amount of hydronium ion H₃O⁺ in a given sample. More the value of hydronium ion concentration, more will be the solution acidic.

On subtracting pH from 14, we get pOH which measures the concentration of hydroxide ion in a given solution. pH depend on the temperature. At room temperature pH scale is between 0 to 14. pH of neutral solution is 7

The concentration of bleach solution  is 1.3×10⁻⁴ M

Concentration of OH⁻=1.3×10⁻⁴ M

Mathematically,

pOH=-log[OH⁻]

Substituting the values

pH=-log[1.3×10⁻⁴]

    =  3.886.

pH+ POH=14

pH=14-3.886.=10.62

Therefore,  the pH of 1.3×10⁻⁴  M  bleach solution is 10.62.

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Answer:

Explanation:

Materials are clothes and heavy rope

Answer:

Metamorphism is the change of minerals or geologic texture (distinct arrangement of minerals) in pre-existing rocks (protoliths), without the protolith melting into liquid magma (a solid-state change). The change occurs primarily due to heat, pressure, and the introduction of chemically active fluids.

Explanation:

i hope this helps :)

Answer:

biological decay

Explanation:

Hope this helps

Answer:

1) SpongeBob’s question is that "what would be the appropriate way to wash his favorite pants as they don't seem as clean as earlier"?

2) SpongeBob’s claim that Clean-O detergent is unable to wash the pants more cleaner as compared to plain water.

3) Independent variable in the given example is the quantity of Clean-O detergent and plain water as it can be changed or manipulated.

4) Dependent variable in the given example is the cleanliness of pants as it will be affected by the quantity of Clean-O detergent and plain water which is an independent variable.

Answer:

713 nm. It is not visible with the naked eye.

Explanation:

Step 1: Given data

Step 2: Calculate the wavelength of the light

We will use the Planck-Einstein equation.

E = h × c / λ

λ = h × c / E

λ = 6.63 × 10⁻³⁴ J.s × 3.00 × 10⁸ m/s / 2.79 × 10⁻¹⁹ J

λ = 7.13 × 10⁻⁷ m

Step 3: Convert "λ" to nm

We will use the relationship 1 m = 10⁹ nm.

7.13 × 10⁻⁷ m × (10⁹ nm/1 m) = 713 nm

This light is not in the 400-700 nm interval so it is not visible with the naked eye.

Answer: 1.13 x 10^5

Explanation:

Answer:

8.937g/cm³

Explanation:

To answer this question we need to know that, in 1 unit FCC cell you have:

Edge length = √8 * R

Volume = 8√8 * R³

And there are 4 atoms per unit cell

Mass of 4 atoms in g:

4 atom * (1mol / 6.022x10²³atom) * (63.55g / mol) = 4.221x10⁻²²g

Volume in cm³:

0.1278nm * (1x10⁻⁷cm / 1nm) = 1.278x10⁻⁸cm

Volume = 8√8 * (1.278x10⁻⁸cm)³

Volume = 4.723x10⁻²³cm³

And density is:

4.221x10⁻²²g / 4.723x10⁻²³cm³ =

Answer:

Density of block of gold is 3.5 g/cm³.

Explanation:

Given data:

Volume of block = 1000 mL

Mass of block = 3.5 kg (3.5×1000 = 3500 g)

Density of block = ?

Solution:

Density of substance is calculated by dividing the mass of substance over its volume.

Formula:

d = m/v

d = 3500 g/ 1000 mL

d = 3.5 g/mL

or

d = 3.5 g/cm³             (1ml = 1cm³)

Answer : The number of moles of precipitate, [tex]PbBr_2[/tex] formed will be 0.01 moles.

Explanation : Given,

Concentration of NaBr = 0.200 M

Volume of solution = 100.0 mL = 0.1 L      (1 L = 1000 mL)

First we have to calculate the moles of NaBr.

[tex]\text{Moles of NaBr}=\text{Concentration of NaBr}\times \text{Volume of solution in L}[/tex]

[tex]\text{Moles of NaBr}=0.200M\times 0.1L=0.02mol[/tex]

Now we have to calculate the moles of precipitate, [tex]PbBr_2[/tex] formed.

The balanced chemical reaction is:

[tex]2NaBr(aq)+Pb(NO_3)_2(aq)\rightarrow PbBr_2(s)+2NaNO_3(aq)[/tex]

From the balanced chemical reaction we conclude that:

As, 2 moles of NaBr react to give 1 mole of [tex]PbBr_2[/tex]

So, 0.02 moles of NaBr react to give [tex]\frac{0.02}{2}=0.01[/tex] mole of [tex]PbBr_2[/tex]

Therefore, the number of moles of precipitate, [tex]PbBr_2[/tex] formed will be 0.01 moles.

The number of mole of the precipitate (i.e PbBr₂) formed when 100 mL of 0.2 M NaBr react with excess Pb(NO₃)₂ is 0.01 mole

Volume = 100 mL = 100 / 1000 = 0.1 L

Molarity of NaBr = 0.2 M

Mole = Molarity x Volume

Mole of NaBr = 0.2 × 0.1

2NaBr(aq) + Pb(NO₃)₂(aq) → PbBr₂(s) + 2NaNO₃ (aq)

From the balanced equation above,

2 moles of NaBr reacted to produce 1 mole of PbBr₂.

Therefore,

0.02 mole of NaBr will react to produce = [tex]\frac{0.02}{2} \\\\[/tex] = 0.01 mole of PbBr₂.

Thus, the number of mole of the precipitate (i.e PbBr₂) produced from the reaction is 0.01 mole

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Answer: Potassium Bromide (KBr) The Ionic bond formed between Potassium and Bromine is created through the transfer of electrons from Potassium (metal) to Bromine (nonmetal).

Explanation: this type of structure departs strongly from that expected for ionic bonding and ... whose roots go back to Max Planck's explanation in 1900 of the properties of ... types of interactions between elementary particles (the strong force, the weak force, ...

Answer:

atom

Explanation:

the atom is the smallest form.