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3 years ago

Which is the best description of a molecule?

1 answer:

3 0

By definition, we have to:
A molecule is a group of at least two atoms in a defined configuration linked by chemical bonds.
We have two types of molecules:
1) several atoms of a single chemical element, as in the case of oxygen. (O2)
2) Atoms of different elements, as in the case of water. (H2O)
Answer:
the best description of a molecule is:
A: A molecule of an element is composed of at least two types of atoms.

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The vapor pressure of pure water at 30°C is 40 torr. If NaCl is dissolved into a sample of water until the total vapor pressure

Dmitry_Shevchenko [17]

Answer:

Mole fraction is 0.2

Explanation:

You have to apply the colligative property about vapour pressure which formula is:

ΔP = P° .Xm

Where ΔP = P° - P

Pressure of vapour from pure solvent (P°) - Pressure of vapour from solution

40 Torr - 32 Torr = 40 Torr . Xm

8 Torr / 40 Torr= 0.2. > Xm

8 0

3 years ago

Rate Law & Reaction Kinetics Chemistry 11 Chapter 17 1. For the reaction 3 ClO - (aq) → ClO - 3(aq) + 2 Cl - (aq) doubling t

ryzh [129]

Answer:

1) Rate = K [ClO⁻]²

2) Rate = K [C6H5N2Cl]

3) - Double the concentration of H3PO4.

- Double the concentration of I⁻

4) Check Explanation

Explanation:

A reaction's rate law is written as a product of the reaction's rate constant, k, and the concentration of the respective reactant(s) raised to the power of the order of reaction.

The order of a reaction with respect to a reactant is the power that the concentration of that specific reactant has in the rate law. It shows how dependent on each reactant , the rate of the reaction.

1) 3ClO⁻ (aq) → ClO³⁻ (aq) + 2 Cl⁻ (aq)

Doubling the concentration of ClO⁻ quadruples the initial rate of formation of ClO³⁻. What is the rate expression for the reaction?

Rate = k [ClO⁻]ⁿ

When [ClO⁻] is doubled, Rate is quadrupled, this shows that the reaction is second order with respect to the only reactant.

Rate = K [ClO⁻]²

2. The reaction

C6H5N2Cl (aq) + H2O (l) → C6H5OH (aq) + N2 (g) + HCl (aq) is first order in C6H5N2Cl and zero order in H2O. What is the rate expression?

Normally, the rate of reaction is equal to the rate constant multiplied by the each reactant's concentration raised ti the power of the order, so,

Rate = K [C6H5N2Cl]¹ [H2O]

Rate = K [C6H5N2Cl]

3. For the reaction

H3PO4 (aq) + 3I⁻ (aq) + 2H + (aq) → H3PO3(aq) + I³⁻(aq) + H2O

(l) the rate expression under certain conditions is R = k[H3PO4][I⁻][H⁺]² . What method(s) could be used if you want to double the reaction rate?

Rate = k[H3PO4][I⁻][H⁺]²

Indicating a first order relationship between the rate and the concentration of H3PO4 & I⁻ and second order with respect to H⁺.

So, any attempt to double the rate of reaction will entail a direct doubling of the one of the reactants with a first order relationship with the rate of reaction.

4. What is the overall order of reaction for each of the following.

a) R = k[NO2]² b) R = k c) R = k[H2][Br2] ½ d) Rate = k[NO]² [O2]

Note that overall order of a reaction is the sum of all the orders of the reactants that appear in the rate law.

a) R = k[NO2]²

Overall order is obviously 2.

b) R = k

Overall order is evidently 0.

c) R = k [H2] [Br2]^ ½

Overall order = 1 + ½ = (3/2)

d) Rate = k[NO]2 [O2]

Overall order = 2 + 1 = 3

Hope this Helps!!!

7 0

3 years ago

When mechanical energy is transformed,

Dafna1 [17]

Answer:

kinetic energy remains unchanged

6 0

3 years ago

How many atoms of oxygen are represented in 2Fe(NO3)2? ( My answer: C) Correct?

astra-53 [7]

How many atoms of oxygen are represented in 2Fe(NO3)2?

Answer: 12

3 0

4 years ago

The chart shows how cliamate change and rising ocean temperature might affect the types of hurricanes we see this century we see

navik [9.2K]

Answer:

Check Explanation

Explanation:

The chart to be used to answer the question is currently missing. After obtaining online, I have attached it to this solution of this question.

From the graph, the prediction shows a negative percent change in the number of category 1 and category 2 & 3 hurricanes (greater than -25% change) and category 4 & 5 hurricanes get a positive percent change of more than +75% change)

Now, taking the statements, one at a time.

A. Which type of hurricane is expected to strike more frequently this century?

From the chart, only category 4 & 5 hurricanes are predicted to have a positive percent change in number, hence, they are the ones expected to strike more frequently in this century.

B) How are hurricanes formed in the atmosphere?

This information cannot be read off from the graph. So, the answer provided isn't from this chart of prediction.

Hurricanes are formed when warm, moist air from the ocean surface begins to rise rapidly, and they encounter cooler air that forces the warm water vapor to condense& form storm clouds with drops of rain.

C) In general, will hurricanes likely become stronger or weaker this century?

The less powerful hurricanes are predicted to have more than 25% negative percent change in number.

But the most powerful categories of hurricanes are predicted to have more than 75% positive percent change in number.

Although, the true figures aren't clear, but more hurricanes that happen are bound to be classified as category 4 & 5 hurricanes. It can be perceived that hurricanes are getting stronger in this century.

D) Which areas are at the highest risk of hurricanes?

This information cannot be read off from this chart. It isn't provided.

E) Which types of hurricanes are expected to drop in frequency by more than 25% this century?

From the chart, category 1 and category 2 & 3 hurricanes are predicted to drop in frequency by more than 25% this century.

F) How many category 4 and 5 hurricanes can we expect this century?

From the chart, we're predicted to have more than 75% positive percent increase in the number of category 4 & 5 hurricanes.

The number of category 4 and 5 hurricanes we should expect this century will be more than 75% higher than the previous century.

Hope this Helps!!!

5 0

3 years ago