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3 years ago

If a hydrogen atom and a helium atom have the same kinetic energy:________

1 answer:

7 0

Answer: If a hydrogen atom and a helium atom have the same kinetic energy then the wavelength of the hydrogen atom will be roughly equal to the wavelength of the helium atom.

Explanation:

The relation between energy and wavelength is as follows.

$E = \frac{hc}{\lambda}\\$

This means that energy is inversely proportional to wavelength.

As it is given that energy of a hydrogen atom and a helium atom is same.

Let us assume that $E_{hydrogen} = E_{helium} = E'$ . Hence, relation between their wavelengths will be calculated as follows.

$E_{hydrogen} = \frac{hc}{\lambda_{hydrogen}}$ ... (1)

$E_{helium} = \frac{hc}{\lambda_{helium}}$ ... (2)

Equating the equations (1) and (2) as follows.

$E_{hydrogen} = E_{helium} = E'\\\frac{hc}{\lambda_{hydrogen}} = \frac{hc}{\lambda_{helium}} = E'\\\lambda_{helium} = \lambda_{hydrogen} = E'$

Thus, we can conclude that if a hydrogen atom and a helium atom have the same kinetic energy then the wavelength of the hydrogen atom will be roughly equal to the wavelength of the helium atom.

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Consider the reaction: 2NO(g) + 2H2(g) → N2(g) + 2H2O(g) A suggested mechanism for this reaction follows: (1) NO(g) + NO(g) → N2

Dominik [7]

Hello. This question is incomplete. The full question is:

"Consider the following reaction. 2NO(g) + 2H2(g) → N2(g) + 2H2O(g)

A proposed reaction mechanism is: NO(g) + NO(g) N2O2(g) fast N2O2(g) + H2(g) → N2O(g) + H2O(g) slow N2O(g) + H2(g) → N2(g) + H2O(g) fast

What is the rate expression? A. rate = k[H2] [NO]2 B. rate = k[N2O2] [H2] C. rate = k[NO]2 [H2]2 D. rate = k[NO]2 [N2O2]2 [H2]"

Answer:

A. rate = k[H2] [NO]2

Explanation:

A reaction mechanism is a term used to describe a set of phases that make up a chemical reaction. In these phases a detailed sequence of each step is shown, composed of several complementary reactions, which occur during a chemical reaction.

These mechanisms are directly related to chemical kinetics and allow changes in reaction rates to be observed in advance.

Reaction rate, on the other hand, refers to the speed at which chemical reactions occur.

Based on this, we can observe through the reaction mechanism shown in the question above, that the action "k [H2] [NO] 2" would have no changes in the reaction rate.

4 0

3 years ago

Phosphorus-32 is radioactive and has a half life of 14.3 days. What percentage of a sample would be left after 12.6 days

nadya68 [22]

Answer:

There is 54.29 % sample left after 12.6 days

Explanation:

Step 1: Data given

Half life time = 14.3 days

Time left = 12.6 days

Suppose the original amount is 100.00 grams

Step 2: Calculate the percentage left

X = 100 / 2^n

⇒ with X = The amount of sample after 12.6 days

⇒ with n = (time passed / half-life time) = (12.6/14.3)

X = 100 / 2^(12.6/14.3)

X = 54.29

There is 54.29 % sample left after 12.6 days

8 0

3 years ago

Suppose a 250. mL flask is filled with 0.30 mol of N_2 and 0.70 mol of NO. The following reaction becomes possible:N_2(g) +O2 →

Inessa [10]

Answer:

0.4 M

Explanation:

Equilibrium occurs when the velocity of the formation of the products is equal to the velocity of the formation of the reactants. It can be described by the equilibrium constant, which is the multiplication of the concentration of the products elevated by their coefficients divided by the multiplication of the concentration of the reactants elevated by their coefficients. So, let's do an equilibrium chart for the reaction.

Because there's no O₂ in the beginning, the NO will decompose:

N₂(g) + O₂(g) ⇄ 2NO(g)

0.30 0 0.70 Initial

+x +x -2x Reacts (the stoichiometry is 1:1:2)

0.30+x x 0.70-2x Equilibrium

The equilibrium concentrations are the number of moles divided by the volume (0.250 L):

[N₂] = (0.30 + x)/0.250

[O₂] = x/0.25

[NO] = (0.70 - 2x)/0.250

K = [NO]²/([N₂]*[O₂])

K = $\frac{(\frac{0.70 -2x}{0.250})^2 }{\frac{0.30+x}{0.250}*\frac{x}{0.250} }$

7.70 = (0.70-2x)²/[(0.30+x)*x]

7.70 = (0.49 - 2.80x + 4x²)/(0.30x + x²)

4x² - 2.80x + 0.49 = 2.31x + 7.70x²

3.7x² + 5.11x - 0.49 = 0

Solving in a graphical calculator (or by Bhaskara's equation), x>0 and x<0.70

x = 0.09 mol

Thus,

[O₂] = 0.09/0.250 = 0.36 M ≅ 0.4 M

3 0

3 years ago

Suppose an ice cube weighing 36.0 g at a temperature of 10°C is placed in 360 g water at a temperature of 20°C. Calculate the te

Scilla [17]

Answer:

10.44 °C

Explanation:

When the thermal equilibrium is reached, both of the substances have the same final temperature (T). The liquid water will lose heat, and the ice cube will absorb this heat. The temperature of the ice will increase until it reaches 0°C, at this temperature, it will change of phase for liquid, absorbing heat, but without a change in the temperature. Then the temperature will increase until the equilibrium.

By the energy conservation, the total amount of heat must be equal to 0:

Qice + Qmelting + Qliquid1 + Qliquid2 = 0

Liquid 1 is the ice after melting, and liquid 2 the liquid that was already at the flask. When there's a change of temperature:

Q = n*c*ΔT, where n is the number of moles, c is the heat capacity and ΔT is the temperature change (final - initial). The temperature variation in °C is equal in K, so the temperature may be used in °C.

The melting heat is:

Q = n*Hfus, Hfus = 6007 J/mol

The molar mass of the water is 18 g/mol, so the number of moles of the water and the ice are:

nwater = nliquid1 = 360/18 = 20 moles

nice = 36/18 = 2 moles

Qice + Qmelting + Qliquid1 + Qliquid2 = 0

2*38*(0 - (-10)) + 2*6007 + 2*75*(T - 0) + 20*75*(T - 20) = 0

760 + 12014 + 150T + 1500T - 30000 = 0

1650T = 17226

T = 10.44 °C

4 0

3 years ago

Magnesium hydroxide is added to a solution of hydrochloric acid. A reaction occurs and magnesium chloride and water are formed.

kodGreya [7K]

Answer:Magnesium (Mg) is a - reactant

Hydrogen (H2) is a - product

magnesium chloride (MgCI2) is a - product

hydrochloric acid (HCI) is a - reactant

Explanation: It’s in my notes

8 0

3 years ago