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3 years ago

Which statement describes a step in the formation of an ionic bond?

2 answers:

7 0

The correct answer is a metal atom forms a cation, and a nonmetal atom forms an anion. This is because metals are less electronegative than nonmetals and will therefore give electrons to nonmetals. Atoms that give up electrons will have a positive charge therefore becoming a cation while atoms that accept electrons will have a negative charge therefore becoming an anion.

Ions that have the same charge can't be attracted to each other since it takes a positive and negative charge to cause attractive forces.

A less electronegative atom will transfer electrons to a more electronegative atom.

A metal (cation) can pull electrons from another metal (not an ion) but that does not form an attractive force between the two metals (You will learn more about this when you go over reduction potentials, redox reactions, and electrochemistry).

I hope this helps. Let me know if anything is unclear.

Svet_ta [14]3 years ago

4 0

The answer is (B) A metal atom forms a cation, and a nonmetal atom forms an anion.

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Name three sources of atmospheric carbon dioxide.

quester [9]

The answer is decomposition, ocean release and respiration. hope this helps u :D

4 0

2 years ago

Calculate the initial rate for the formation of C at 25 ∘C, if [A]=0.50M and [B]=0.075M.Express your answer to two significant f

N76 [4]

The question is incomplete, here is the complete question:

Calculate the initial rate for the formation of C at 25°C, if [A]=0.50 M and [B]=0.075 M. Express your answer to two significant figures and include the appropriate units.Consider the reaction

A + 2B ⇔ C

whose rate at 25°C was measured using three different sets of initial concentrations as listed in the following table:

The table is attached below as an image.

<u>Answer:</u> The initial rate for the formation of C at 25°C is $2.25\times 10^{-2}Ms^{-1}$

<u>Explanation:</u>

Rate law is defined as the expression which expresses the rate of the reaction in terms of molar concentration of the reactants with each term raised to the power their stoichiometric coefficient of that reactant in the balanced chemical equation.

For the given chemical equation:

$A+2B\rightleftharpoons C$

Rate law expression for the reaction:

$\text{Rate}=k[A]^a[B]^b$

where,

a = order with respect to A

b = order with respect to B

Expression for rate law for first trial:

$5.4\times 10^{-3}=k(0.30)^a(0.050)^b$ ....(1)

Expression for rate law for second trial:

$1.1\times 10^{-2}=k(0.30)^a(0.100)^b$ ....(2)

Expression for rate law for third trial:

$2.2\times 10^{-2}=k(0.50)^a(0.050)^b$ ....(3)

Dividing 2 by 1, we get:

$\frac{1.1\times 10^{-2}}{5.4\times 10^{-3}}=\frac{(0.30)^a(1.00)^b}{(0.30)^a(0.050)^b}\\\\2=2^b\\b=1$

Dividing 3 by 1, we get:

$\frac{2.2\times 10^{-2}}{5.4\times 10^{-3}}=\frac{(0.50)^a(0.050)^b}{(0.30)^a(0.050)^b}\\\\4.07=2^a\\a=2$

Thus, the rate law becomes:

$\text{Rate}=k[A]^2[B]^1$ ......(4)

Now, calculating the value of 'k' by using any expression.

Putting values in equation 1, we get:

$5.4\times 10^{-3}=k[0.30]^2[0.050]^1\\\\k=1.2M^{-2}s^{-1}$

Calculating the initial rate of formation of C by using equation 4, we get:

$k=1.2M^{-2}s^{-1}$

[A] = 0.50 M

[B] = 0.075 M

Putting values in equation 4, we get:

$\text{Rate}=1.2\times (0.50)^2\times (0.075)^1\\\\\text{Rate}=2.25\times 10^{-2}Ms^{-1}$

Hence, the initial rate for the formation of C at 25°C is $2.25\times 10^{-2}Ms^{-1}$

8 0

3 years ago

Calculate the change in pH when 71.0 mL of a 0.760 M solution of NaOH is added to 1.00 L of a solution that is 1.0O M in sodium

Eddi Din [679]

Explanation:

It is known that $pK_{a}$ value of acetic acid is 4.74. And, relation between pH and $pK_{a}$ is as follows.

pH = pK_{a} + log $\frac{[CH_{3}COOH]}{[CH_{3}COONa]}$

= 4.74 + log $\frac{1.00}{1.00}$

So, number of moles of NaOH = Volume × Molarity

= 71.0 ml × 0.760 M

= 0.05396 mol

Also, moles of $CH_{3}COOH$ = moles of $CH_{3}COONa$

= Molarity × Volume

= 1.00 M × 1.00 L

= 1.00 mol

Hence, addition of sodium acetate in NaOH will lead to the formation of acetic acid as follows.

$CH_{3}COONa + NaOH \rightarrow CH_{3}COOH$

Initial : 1.00 mol 1.00 mol

NaoH addition: 0.05396 mol

Equilibrium : (1 - 0.05396 mol) 0 (1.00 + 0.05396 mol)

= 0.94604 mol = 1.05396 mol

As, pH = pK_{a} + log $\frac{[CH_{3}COONa]}{[CH_{3}COOH]}$

= 4.74 + log $\frac{0.94604}{1.05396}$

= 4.69

Therefore, change in pH will be calculated as follows.

pH = 4.74 - 4.69

= 0.05

Thus, we can conclude that change in pH of the given solution is 0.05.

8 0

2 years ago

A container of gas is initially at 0.25 atm and 0 ˚C. What will the pressure be at 125 ˚C?

Pani-rosa [81]

Answer:

0.37atm

Explanation:

Given parameters:

Initial pressure = 0.25atm

Initial temperature = 0°C = 273K

Final temperature = 125°C = 125 + 273 = 398K

Unknown:

Final pressure = ?

Solution:

To solve this problem, we use a derivative of the combined gas law;

$\frac{P1}{T1}$ = $\frac{P2}{T2}$

P and T are pressure and temperature

1 and 2 are initial and final values

$\frac{0.25}{273}$ = $\frac{P2}{398}$

P2 = 0.37atm

3 0

2 years ago

Which one of these are correct base pairs in DNA?

Arisa [49]

Base pairs of DNA are A with T, and C with G

here's how to remember:

Apple - Tree
Car - Garage

8 0

3 years ago