Observe: Click Reset (). The electrons in the outermost orbit, called valence electrons, help to create chemical bonds. Create a lithium atom (3 protons, 4 neutrons, 3 electrons). How many valence electrons are in a neutral lithium atom?

Answer:

[tex]1 \: l \: contains \: 0.20 \: moles \: of \: HOCN \\ 0.03 \: l \: will \: contain \: (0.03 \times 0.20) \: moles \\ = 0.006 \: moles \: of \: HOCN \\ 1 \: l \: contains \: 0.250 \: moles \: of \: potassium \: hydroxide \\ 0.01 \: l \: will \: contain \: (0.01 \times 0.250) \\ = 0.0025 \: moles \: of \: potassium \: hydroxide \\ KOH + HOCN → KCN + H _{2}O \\ k _{b} = \frac{[K {}^{ + } ][OH {}^{ - } ]}{[KOH]} \\ moles \: of \: OH {}^{ - } \: remaining = 0.006 - 0.0025 \\ = 0.0035 \: moles \\ total \: volume = 0.03 + 0.01 \\ = 0.04 \: litres \\ 0.04 \: l \: contains \: 0.0035 \: moles \\ 1 \: l \: will \: contain \: ( \frac{1 \times 0.0035}{0.04} ) \\ = 0.0875 \: mol \: per \: litre \\ [H {}^{ + } ] = \frac{kw}{[OH {}^{ - } ]} \\ = \frac{1 \times {10}^{ - 14} }{0.0875} \\ = 1.143 \times {10}^{ - 13} \\ pH = - log(1.143 \times {10}^{ - 13} ) \\ pH = 12.94[/tex]

Explanation:

2H2O and 0.722g of Na3PO4.12H20 mix with water forming 500 mL of solution, how many grams of Ba3(. ... Forming 500 ML Of Solution, How Many Grams Of Ba3(PO4)2 Precipitate?

When 0.421 g of BaCl₂ · 2 H2O and 0.722g of Na₃PO₄ · 12 H₂O mix with water forming 500 mL of solution then 0.003 mol/L of Ba₃(PO4)₂ precipitate.

Stoichiometry is an important concept which helps us use the balanced chemical equation to measures the amount of reactants and products.

Molarity of solution is the number of moles of solute per liter of solution. Molarity is also called Molar Concentration.

Molarity (M) = [tex]\frac{\text{number of moles}}{\text{volume of solution (in liters)}}[/tex]

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

First we have to write the balanced chemical equation

2Na₃PO₄ · 12 H₂O + 3BaCl₂ · 2 H2O → Ba₃(PO4)₂ + 6 NaCl + 30 H₂O

Here 3 moles of BaCl₂ · 2 H2O produce 1 mole of Ba₃(PO4)₂

So,

Number of moles of BaCl₂ · 2 H2O = [tex]\frac{\text{Mass of}\ BaCl_2 . 2H_2O}{\text{Molar mass of}\ BaCl_2. 2H_2O}[/tex]

                                                           =  [tex]\frac{0.421}{244.26}[/tex]

                                                           = 0.017

Number of moles of 2Na₃PO₄ · 12 H₂O = [tex]\frac{\text{Mass of}\ Na_3PO_4. 12H_2O}{\text{Molar mass of}\ Na_3PO_4 . 12H_2O}[/tex]

                                                                 = [tex]\frac{0.722}{380.12}[/tex]

                                                                 = 0.002

Therefore, Na₃PO₄ · 12 H₂O is the limiting reagent.

Now, put the value in above formula to find the molarity

Molarity (M) = [tex]\frac{\text{number of moles}}{\text{volume of solution (in liters)}}[/tex]

                    = [tex]\frac{0.0017}{0.5}[/tex]

                    = 0.003 mol/L

Thus, from above conclusion we can say that 0.003 mol/L of Ba₃(PO4)₂ precipitate.

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Answer:

The lowest point on a wave?

The lowest point on the wave is called as through or wave through.

The highest point on the wave is known as the crest or wave crest

The space between the crests is called the wave length.

The distance between the wave crest and the wave trough is called the wave height.

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Answer:

Trough

Explanation:

The trough is the lowest point on a wave. The highest point on a wave is called a crest.

Answer:

When the moles of the reactant is equal to the mole of the product.

Answer:

pH = 0.90

Explanation:

The NH3 reacts with nitric acid, HNO3 as follows:

NH3 + HNO3 → NH₄⁺ + NO₃⁻

Where 1 mole of NH3 reacts per mole of HNO3.

The moles added of each reactant are:

Moles NH3:

100mL = 0.100L * (0.050mol / L) = 0.0050 moles NH3

Moles HNO3:

20mL = 0.0200L * (1.00mol / L) = 0.0200 moles HNO3

That means HNO3 is the excess reactant and, after the reaction, its moles are:

0.0200mol - 0.0050mol = 0.0150 moles HNO3

In a final volume of 120mL = 0.120L, the molar concentration of HNO3 is:

0.0150 moles HNO3 / 0.120L = 0.125M HNO3

As nitric acid is a strong acid, [HNO3] = [H+]

[H+] = 0.125M

pH = -log[H+]

To solve this we must be knowing each and every concept related to  chemical formula. Therefore, in the above given ways the chemical formula for the molecule can be written.

A chemical formula is a scientific notation that uses atomic symbol and numerical subscripts to represent the number and types of elements contained in a molecule. A chemical formula seems to be a concise written description of an existing three-dimensional molecule.

A chemical formula characterizes a material to the atomic level. There are three sorts of chemical formulas: empirical, molecular, and structural.

The chemical formula for the given molecules are:

2. H[tex]_2[/tex]O

3. O[tex]_3[/tex]

4. H[tex]_2[/tex]

5. CO[tex]_2[/tex]

6. CO

7. NO[tex]_2[/tex]

8. CH[tex]_4[/tex]

Therefore, in the above given ways the chemical formula for the molecule can be written.

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A student enters the canteen and buys iced tea. He then goes on to add more sugar to his iced tea. In this solution, iced tea is the solvent and sugar is the solute.

Answer:

Rank from lowest to highest - c<a<d<b

Explanation:

Molarity is basically the moles of the solute dissolved in a solvent. Molar mass of NaOH = 39.997 g/mol

a) 6.625 g NaOH dissolved in 250. mL of water

Molarity = 6.625 grams */( 0.250 *39.997) g/mol = 0.66

b) 63.0 g of NaOH dissolved in 1.00 L of water

Molarity = 63 grams */( 1 *39.997) g/mol = 1.575

c) 8.00 g of NaOH dissolved in 500. mL of water

Molarity = 8 grams */( 0.5 *39.997) g/mol = 0.331

d) 0.0530 of NaOH in 100 mL of water = 0.53

Rank from lowest to highest - c<a<d<b

Two airplanes are flying in the sky in such a way that the gravitational attractions between them decreases. The planes must be flying away from each other. Hence option A is correct.

Gravitational attraction is defined as a basic interaction that pulls everything with mass or energy in the same direction. All objects are subject to gravitational interactions, the strength of which is directly inversely proportional to the product of their masses. The size of an object and the separation between the objects have an impact on gravity.

In order to reduce the gravitational pull, two planes are flying in the sky. There must be a directionality between the aircraft. No matter what is in between the two bodies, there will still be gravitational pull. As a result, even if the medium between the two bodies changed, the gravitational force between them would not.

Thus, two airplanes are flying in the sky in such a way that the gravitational attractions between them decreases. The planes must be flying away from each other. Hence option A is correct.

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Answer:

Im not sure if im right but i think its Ca

Explanation:

The question is incomplete, the complete question is;

And a copper electrode with 0.500 M Cu²⁺ as the second half cell

Cu²⁺(aq) + 2 e⁻ → Cu(s) E°red= 0.337 V

The measured cell potential when the water sample was placed into the silver side of the cell was 0.0925 V.

A- What is the standard cell potential for this cell in V?

B- What is the value of the standard free energy (in kJ) for this reaction?

C- Write the balanced equation for the overall reaction in acidic solution?

D- And the measured cell potential is 0.0925, what is the concentration of chloride ions in the solution?

Answer:

See Explanation

Explanation:

a) E°cell = E°cathode - E°anode

E°cell = 0.337 V - 0.2223 V

E°cell = 0.1147 V

b) ΔG°cell = −nFE°cell

Where n=2 and F = 96500C

ΔG°cell =-(2 * 96500 *  0.1147 )

ΔG°cell =-22,137.1 J or -22.1371 KJ

c) 2Ag(s) + 2Cl⁻(aq) + Cu²⁺(aq) -----> 2AgCl(s) + Cu(s)

d) From Nernst Equation;

E= E°cell - 0.0592/n  log Q

0.0925  =  0.1147 - 0.0592/2 log 1/[0.500] [Cl⁻]^2

0.0925 - 0.1147 = - 0.0592/2 log 1/[0.500] [Cl⁻]^2

-0.0222 = -0.0296 log 1/[0.500] [Cl⁻]^2

-0.0222/-0.0296 = log 1/[0.500] [Cl⁻]^2

0.75 = log 1/[0.500] [Cl⁻]^2

Antilog (0.75) = 1/[0.500] [Cl⁻]^2

5.6234 * 0.500 =  [Cl⁻]^2

[Cl⁻] = √2.8117

[Cl⁻] = 1.68 M

A galvanic cell is a voltaic cell that produces electrical energy from the oxidation-reduction process. The standard cell potential of the cell is 0.1147 V.

The standard cell potential is a difference between the electrode potential of the cathode and the anode of the cell.

The balanced overall reaction of the cell is given as,

[tex]\rm 2Ag(s) + 2Cl^{-}(aq) + Cu^{2+}(aq) \rightarrow 2AgCl(s) + Cu(s)[/tex]

The standard cell potential is calculated as:

[tex]\begin{aligned} \rm E^{\circ}cell &= \rm E^{\circ}cathode - E^{\circ} anode\\\\&= 0.337 - 0.2223 \\\\&= 0.1147\;\rm V\end{aligned}[/tex]

Therefore, 0.1147 V is the standard cell potential for the cell.

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Answer: 2. The outermost shell

Explanation:

In an elements ground state, its electrons have the least amount of energy that they could have so they stay in their shells. When Krypton is in this state therefore, its valence electrons will stay in the outermost shell.

As Krypton has a total of 36 electrons in this state, there will be 8 valence electrons and they will all be in the outer shell.

Answer:

Option A. The specific heat is 0.897 J/gºC, The Substance is aluminum.

Explanation:

We'll begin by calculating the change in temperature of the substance. This can be obtained as follow:

Initial temperature (T₁) = 20.0 °C

Final temperature (T₂) = 40.0 °C

Change in temperature (ΔT) =?

ΔT = T₂ – T₁

ΔT = 40 – 20

ΔT = 20 °C

Finally, we shall determine the specific heat capacity of the substance. This can be obtained as follow:

Mass (M) = 136 g

Change in temperature (ΔT) = 20 °C

Heat (Q) absorbed = 2440 J

Specific heat capacity (C) =?

Q = MCΔT

2440 = 136 × C × 20

2440 = 2720 × C

Divide both side by 2720

C = 2440 / 2720

C = 0.897 J/gºC

Comparing the specific heat capacity (i.e 0.897 J/gºC) of the substance with those in the table above, the substance is Aluminum.

Thus, option A gives the correct answer to the question.

Answer:

We learned that waterhas three states: ice is the solid state, watervapor is the gaseous state, and wateris the liquid state. When water is heatedit evaporates, which means it turns into watervapor and expands. Secondly, does water expand when heated?

Explanation:

Answer:

A force is a push or pull that can cause an object to move, stop, or change speed or direction.

I think it's Force.

Answer:

0.034 L

Explanation:

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

Initial volume (V₁) = 0.055 L

Initial pressure (P₁) = stp = 1 atm

Initial temperature (T₁) = stp = 273 K

Final pressure (P₂) = 2.8 atm

Final temperature (T₂) = 195 °C = 195 °C + 273 = 468 K

Final volume (V₂) =?

The final volume of the gas can be obtained as follow:

P₁V₁ / T₁ = P₂V₂ / T₂

1 × 0.055 / 273 = 2.8 × V₂ / 468

0.055 / 273 = 2.8 × V₂ / 468

Cross multiply

273 × 2.8 × V₂ = 0.055 × 468

764.4 × V₂ = 25.74

Divide both side by 764.4

V₂ = 25.74 / 764.4

V₂ = 0.034 L

Therefore, the new volume of the gas is 0.034 L.

Answer:

first the right answer is

Li + H2O = LiOH + H2O

then to balance it...

2 Li + 2 H2O = 2 LiOH + H2

so that we can have both side of the equation to be equal....

HOPE ITS HELPS....

Answer:

[tex]FeCl₃ + (NH₄)₂CO₃ → NH₄Cl + Fe₂(CO₃)₃[/tex]

first balance the chemical equation

first balance the chemical equation[tex]2FeCl₃ + 3(NH₄)₂CO₃ → 6NH₄Cl + Fe₂(CO₃)₃[/tex]

2FeCl₃=2*162=324g

6NH₄Cl=6*53.5=321g

324 g of FeCl₃ gives 321 g of NH₄Cl

200g of FeCl₃ gives 321/324*200=198.14 g of NH₄Cl

in nearest value it is 198g/mole

Answer:

c 18.0ml

Explanation:

The average mass of one H2O molecule is 18.02 amu. The number of atoms is an exact number, the number of mole is an exact number; they do not affect the number of significant figures. The average mass of one mole of H2O is 18.02 grams. This is stated: the molar mass of water is 18.02 g/mol.

Answer:

The answer is C

Explanation:

The more space the molecules have the faster they will move, solid doesn't allow movement at all, when it gets to liquid they are free to move around because it's more space, when a gas they can move all around in the air.

Answer:

28.55 mL or 0.02855 L

Explanation:

Applying,

Density(D) = mass(m)/Volume(V)

D = m/V............... Equation 1

Where D = Density of the Bromine, m = mass of the bromine, V = volume of the bromine

make V the subeject of the equation

V = m/D............. Equation 2

From the question,

Given: m = 88.5 g, D = 3.10 g/mL

Substitute these values into equation 2

V = 88.5/3.10

V = 28.55 mL

Hence the volume occuppied by the Bromine gas is  28.55 mL or 0.02855 L

Answer:

I think:

CH3COCH2CH2CH3 belongs to ketone because it has a carbonyl group C=O in its structure.

Answer:

Explanation:

Decomposition is the answer.

If a compound breaks into two or more parts then it is called decomposition.

Answer:

1.20 × 10³ torr

Explanation:

Step 1: Given data

Step 2: Calculate the final pressure of the gas

Considering the constant volume, if we assume the gas behaves ideally, we can calculate its final pressure using Gay-Lussac's law.

P₁/T₁ = P₂/T₂

P₂ = P₁ × T₂/T₁

P₂ = 822 torr × 475 K/325 K = 1.20 × 10³ torr

Answer:

I think you forgot to post the question or picture

Answer:

[tex]\mathbf{FeCl_3 + AgNO_3 \to 3 AgCl+Fe(NO_3)_3}[/tex]

Explanation:

From the given question,

The chemical equation is:

[tex]\mathbf{FeCl_3 + AgNO_3 \to 3 AgCl+Fe(NO_3)_3}[/tex]

We are given that:

mass of [tex]FeCl_3[/tex] = 45 g

number of moles of [tex]FeCl_3[/tex]  = 45 g/162.2 g/mol

= 0.28 mol

mass of [tex]AgNO_3[/tex] = 25g

number of moles of [tex]AgNO_3[/tex]  = 25/169.87

= 0.147 mol

From the given equation 1 mole of [tex]FeCl_3[/tex] is required to make 3 mole of [tex]AgNO_3[/tex]  

0.28 mole of [tex]FeCl_3[/tex] = 0.28 × 3 = 0.84 mol of [tex]AgNO_3[/tex]  

Here [tex]AgNO_3[/tex]  is the limiting reagent.

Thus,

3 mole of [tex]AgNO_3[/tex]  = 3 moles of AgCl

0.147 mole of [tex]AgNO_3[/tex] = 0.147 mole of AgCl produced.