A neutral charge by an atom is caused by which of the following conditions? a. presence of neutrons in the nucleus
b. balance in number of protons and neutrons
c. balance in number of electrons and protons
d. the balance of electrons in each electron shell

Great amounts of atomic energy are released when a _______reaction occurs.

Great amounts of atomic energy are released when a chemical reaction occurs. The process can be an exothermic reaction or endothermic reaction depending on the substances involved in the reaction.

Answer:

For a: The mass percent of NaBr is 7.03 %

For b: The mass percent of KCl is 16.94 %

For c: The mass percent of toluene is 13.43 %

Explanation:

To calculate the mass percentage of solute in solution, we use the equation:

        .......(1)

• For a:

We are given:

Mass of NaBr (Solute) = 5.50 g

Mass of solution = 78.2 g

Putting values in equation 1, we get:

Hence, the mass percent of NaBr is 7.03 %

• For b:

We are given:

Mass of KCl (Solute) = 31.0 g

Mass of water (solvent) = 152 g

Mass of solution = (31.0 + 152) g = 183 g

Putting values in equation 1, we get:

Hence, the mass percent of KCl is 16.94 %

• For c:

We are given:

Mass of toluene (Solute) = 4.5 g

Mass of benzene (solvent) = 29 g

Mass of solution = (4.5 + 29) g = 33.5 g

Putting values in equation 1, we get:

Hence, the mass percent of toluene is 13.43 %

Final answer:

To calculate the percent by mass of the solute in each aqueous solution, divide the mass of the solute by the mass of the solution and multiply by 100%

Explanation:

To calculate the percent by mass of the solute in each aqueous solution, you'll need to use the formula:

Percent by mass = (mass of solute/mass of solution) x 100%

For example, in solution (a) with 5.50 g of NaBr in 78.2 g of solution, the mass of the solute is 5.50 g and the mass of the solution is 78.2 g. Plugging these values into the formula gives:

Percent by mass = (5.50 g / 78.2 g) x 100% = 7.03%

Similarly, you can calculate the percent by mass for solutions (b) and (c) using the same formula.

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Answer:

1.74845

Explanation:

We have the following reaction:

I2 + H2 => 2 HI

Now, the constant Kc, has the following formula:

Kc = [C] ^ c * [D] ^ d / [A] ^ a * [B] ^ b

In this case I2 is A, H2 is B and C is HI

We know that the values are:

 H2 = 1 × 10 ^ -3 at 448 ° C

I2 = 2 × 10 ^ -3 at 448 ° C

HI = 1.87 × 10 ^ -3 at 448 ° C

Replacing:

Kc = [1.87 × 10 ^ -3] ^ 2 / {[2 × 10 ^ -3] ^ 1 * [1 × 10 ^ -3] ^ 1}

Kc = 1.87 ^ 2/2 * 1

Kc = 1.74845

Which means that at 448 ° C, Kc is equal to 1.74845

Answer:

Explanation:

[H2] = 10^-3

[I2] = 2*10^-3

[HI] = 0

in equilbiirum

[H2] = 10^-3 - x

[I2] = 2*10^-3 -x

[HI] = 0 + 2x

and we know

[HI] = 0 + 2x = 1.87*10^-3

x = ( 1.87*10^-3)/2 =  0.000935

then

[H2] = 10^-3 - 0.000935 = 0.000065

[I2] = 2*10^-3 -0.000935 = 0.001065

                        H₂                +          I              ⇄              2 HI

Initially     1 × 10⁻³                       2 × 10⁻³

Change  -9.35 × 10⁻⁴               -9.35 × 10⁻⁴                +1.87 × 10⁻³

At equil   6.5 × 10⁻⁵                  1.06 5 × 10⁻³               1.87 × 10⁻³

HI increase by 1.87 × 10⁻³M

The breaking and making of chemical bonds can explain chemical reactions and energy flow. a. True b. False

True

The initial volume of the gas is 117L.

What is volume?

Volume is the amount of space the matter occupies.

What do you mean by combined gas law?

• The combined gas law combines the three gas laws: Boyle's Law, Charles' Law, and Gay-Lussac's Law.
• It states that the ratio of the product of pressure and volume and the absolute temperature of a gas is equal to a constant.
• When Avogadro's law is added to the combined gas law, the ideal gas law results.
• It is a combination of the other gas laws that works when everything except temperature, pressure, and volume are kept constant.
• There are a couple of common equations for writing the combined gas law. The classic law relates Boyle's law and Charles' law to state:

                                     PV/T = k

where P = pressure, V = volume, T = absolute temperature in K and k= constant.

• Another common formula for the combined gas law relates before and after conditions of a gas:

          P1V1 / T1 = P2V2 / T2

Where P1 and P2 = initial and final pressure in atm

           T1 and T2 = Initial and final temperature in K

            V1 and V2 = initial and final volume in L

Using combined gas law:

P1V1/T1 = P2V2/T2

Given:

P1 = 0.5 atm

T1 = 325K

P2 = 1.2 atm

V2 = 48L

T2 = 320K

Assuming that the number of moles are constant for both conditions:

(P1 x V1)/T1 = (P2 x V2)/T2

Substituting the given values,

(0.5 x V1)/325 = (1.2 x 48)/320K

Solving for V1

V1 = (1.2atm x 48L x 325K)/ (320Kx 0.5 atm)

 V1   = 117L

 Hence, the initial volume of the gas is 117L.

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