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2 years ago

Elements and molecules will always reemit the exact radiation that they

1 answer:

4 0

Elements/molecules will absorb a photon if energy, which will put them into an excited state. They will then emit that same energy back in order to come back down to their ground state energy.

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Complete the dissociation reaction and the corresponding Ka equilibrium expression for each of the following acids in water. (Ty

anastassius [24]

Answer :

(A) The dissociation reaction of $HC_2H_3O_2$ will be:

$HC_2H_3O_2(aq)\rightleftharpoons H^+(aq)+C_2H_3O_2^-(aq)$

The equilibrium expression :

$K_a=\frac{[H^+][C_2H_3O_2^-]}{[HC_2H_3O_2]}$

(B) The dissociation reaction of $Co(H_2O)_6^{3+}$ will be:

$Co(H_2O)_6^{3+}(aq)\rightleftharpoons H^+(aq)+Co(H_2O)_5(OH)^{2+}(aq)$

The equilibrium expression :

$K_a=\frac{[H^+][Co(H_2O)_5(OH)^{2+}]}{[Co(H_2O)_6^{3+}]}$

(C) The dissociation reaction of $CH_3NH_3^+$ will be:

$CH_3NH_3^+(aq)\rightleftharpoons H^+(aq)+CH_3NH_2(aq)$

The equilibrium expression :

$K_a=\frac{[H^+][CH_3NH_2]}{[CH_3NH_3^+]}$

Explanation :

Equilibrium constant : It is defined as the equilibrium constant. It is defined as the ratio of concentration of products to the concentration of reactants.

The equilibrium expression for the reaction is determined by multiplying the concentrations of products and divided by the concentrations of the reactants and each concentration is raised to the power that is equal to the coefficient in the balanced reaction.

As we know that the concentrations of pure solids and liquids are constant that is they do not change. Thus, they are not included in the equilibrium expression.

(A) The dissociation reaction of $HC_2H_3O_2$ will be:

$HC_2H_3O_2(aq)\rightleftharpoons H^+(aq)+C_2H_3O_2^-(aq)$

The equilibrium expression of $HC_2H_3O_2$ will be:

$K_a=\frac{[H^+][C_2H_3O_2^-]}{[HC_2H_3O_2]}$

(B) The dissociation reaction of $Co(H_2O)_6^{3+}$ will be:

$Co(H_2O)_6^{3+}(aq)\rightleftharpoons H^+(aq)+Co(H_2O)_5(OH)^{2+}(aq)$

The equilibrium expression of $Co(H_2O)_6^{3+}$ will be:

$K_a=\frac{[H^+][Co(H_2O)_5(OH)^{2+}]}{[Co(H_2O)_6^{3+}]}$

(C) The dissociation reaction of $CH_3NH_3^+$ will be:

$CH_3NH_3^+(aq)\rightleftharpoons H^+(aq)+CH_3NH_2(aq)$

The equilibrium expression of $CH_3NH_3^+$ will be:

$K_a=\frac{[H^+][CH_3NH_2]}{[CH_3NH_3^+]}$

3 0

3 years ago

How many moles of calcium carbonate-CaCO3 = 4.15 g

marin [14]

Answer:

Number of moles = 0.042 mol

Explanation:

Given data:

Number of moles = ?

Mass of calcium carbonate = ?

Solution:

Formula:

Number of moles = mass/ molar mass

now we will calculate the molar mass of calcium carbonate.

atomic mass of Ca = 40 amu

atomic mass of C = 12 amu

atomic mass of O = 16 amu

CaCO₃ = 40 + 12+ 3×16

CaCO₃ = 40 + 12+48

CaCO₃ = 100 g/mol

Now we will calculate the number of moles.

Number of moles = 4.15 g / 100 g/mol

Number of moles = 0.042 mol

3 0

3 years ago

24. 00 ml of a 0. 25 m naoh solution is titrated with 0. 10m hcl. What is the ph of the solution after 24. 00 ml of the hcl has

12345 [234]

pH of the solution after 24. 00 ml of the hcl has been added is 12.87

millimoles NaOH = mL x M = 24.00 mL x 0.25 M = 6.00

millimoles HCl = 24.00 mL x 0.10 M = 2.40

total volume = 48.00 mL

.................................NaOH + HCl ==>NaCl + H2O

initial.........................6.00.........0............0.........0

added.....................................2.40............................

change.................... -2.40......-2.40.........+2.40.... +2.40

equilibrium.................3.60.........0..............2.40.......2.40

The NaCl contributes nothing to the pH of the final solution. The pH is determined by the excess of NaOH present. (NaOH) = millimoles/mL = 3.60/48.00 = 0.075 M = (OH^-)

pOH = -log (OH^-). Then

pOH = -log (0.075)

pOH =1.1249

As we know,

pH + pOH = pKw = 14.00

pH=14-pOH

pH=14-1.1249

pH=12.87

pH is a logarithmic measure of an aqueous solution's hydrogen ion concentration. pH = -log[H+], where log is the base 10 logarithm and [H+] is the concentration of hydrogen ions in moles per liter.

The pH of an aqueous solution describes how acidic or basic it is, with a pH less than 7 being acidic and a pH greater than 7 being basic. A pH of 7 is regarded as neutral (e.g., pure water). pH values typically range from 0 to 14, though very strong acids may have a negative pH and very strong bases may have a pH greater than 14.

Learn more about pH:

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7 0

1 year ago

M,,,,,,,,,mmmmmmmmmmmmmmmmmmmmmmmmmmmmm

Varvara68 [4.7K]

What is this?????????????

8 0

2 years ago

2. What mass of sodium chloride is produced when chlorine gas reacts with 2.29 grams of sodium iodide? The unbalanced equation i

Damm [24]

Answer:

0.88g

Explanation:

The reaction equation:

2NaI + Cl₂ → 2NaCl + I₂

Given parameters:

Mass of Sodium iodide = 2.29g

Unknown:

Mass of NaCl = ?

Solution:

To solve this problem, we work from the known to the unknown.

First find the number of NaI from the mass given;

Number of moles = $\frac{mass}{molar mass}$

Molar mass of NaI = 23 + 126.9 = 149.9g/mol

Now insert the parameters and solve;

Number of moles = $\frac{2.29}{149.9}$ = 0.015mol

So;

From the balanced reaction equation;

2 moles of NaI produced 2 moles of NaCl

0.015mole of NaI will produce 0.015mole of NaCl

Therefore;

Mass = number of moles x molar mass

Molar mass of NaCl = 23 + 35.5 = 58.5g/mol

Now;

Mass of NaCl = 0.015 x 58.5 = 0.88g

8 0

2 years ago