During a combustion reaction, 9.00 grams of oxygen reacted with 3.00 grams of CH4.

B, C

Explanation:

The Lewis dot structures that are valid are for B and C.

Regarding A;

The Lewis representation of carbon is correct. Each of the four dots symbolizes the four valence electrons.

However, the nitrogen with a single dot above, to the left, and below and a -3 charge isincorrect. For it to have a -3 charge, it must possess 8 Lewis dots (two on each side).

The nitrogen showing four dots (on top, right, bottom and left) is incorrect.

In B;

An oxygen having two dots positioned above and below with one dot on both sides is correct , as the 6 dots indicate oxygen's valence electrons.

In C;

A carbon shows two dots at each position and has a charge of +4. This is correct because the charge reflects that it has gained four electrons giving it 8 valence electrons.

In D;

An oxygen shows two dots above, to the left and below, with a charge of -2. This is incorrect as not all Lewis dots are present. Two are missing.

Answer:

The categorization of strong, weak, and non-electrolytes is detailed below, based on the examples presented in the question.

Explanation:

A strong electrolyte fully dissociates or nearly so in an aqueous environment; typically, strong acids, bases, and salts fall under this category. Examples of strong electrolytes include:

• Hydrochloric acid, HCl
• Calcium hydroxide, Ca(OH)2
• Potassium chloride, KCl

A weak electrolytepartially ionizes in solution; weak acids and bases are primary instances. Examples consist of:

• Methylamine, CH3NH2
• Hydrofluoric acid, HF

A non-electrolytedoes not dissociate in an aqueous medium. Examples of non-electrolytes are:

• Sucrose, C12H22O11
• Methanol, CH3OH

Answer:

The enthalpy of the second intermediate equation is altered by halving its value and changing the sign.

Explanation:

Let's examine both the first and second intermediate reactions alongside the overall equation concerning the examined process;

First reaction;

Ca (s) + CO₂ (g) + ½O₂ (g) → CaCO₃ (s) ΔH₁ = -812.8 kJ

Second reaction;

2Ca (s) + O₂ (g) → 2CaO (s) ΔH₂ = -1269 kJ

Thus, the overall reaction becomes;

CaO (s) + CO₂ (g) → CaCO₃ (s) ΔH =?

According to Hess's law, which states that the total heat change in a reaction is equal to the sum of the heat changes for each step, we cannot simply sum the enthalpies for this overall reaction. Instead, we obtain the overall enthalpy by halving the second intermediate reaction's enthalpy and changing its sign before adding, as illustrated below;

Enthalpy of Intermediate reaction 1 + ½(-Enthalpy of Intermediate reaction 2) = Enthalpy of Overall reaction

Answer:- 0.134 seconds

Solution:- The speed is given as and the circumference is 24900 miles which is same as the distance light have to covered. It asks to calculate the time required to cover this distance by the light.

Unit conversion is needed from miles to meters since the speed is given in meters per second.

1 mile = 1609.34 meters

Thus,

= 40072566 meters

Now,

Rearranged for time, that gives:

Inserting the values:

= 0.134 seconds

Hence, light would take 0.134 seconds to traverse the indicated distance. The answer without the unit is 0.134.

Greetings!

The result is:

The new volume is:

Rationale:

Because the temperature remains constant, we can apply Boyle's Law to solve this issue.

Boyle's Law stipulates that:

Where,

P is the gas's pressure.

V is the gas's volume.

According to the information provided:

Let's put the values into the equation:

Consequently, the new volume is:

Wishing you a lovely day!