Correct Answer: B. personal interaction and information gathering

Correct Answer: D. Law of Moses

Correct Answer: D) 71

Explanation

To calculate the relative molecular mass of the gas, we first need to determine the number of moles of the gas. We can do this using the given mass of the gas and the molar volume of the gas at standard temperature and pressure (s.t.p).

At s.t.p, one mole of any gas occupies a volume of 22.4 dm\(^3\), which is equivalent to 22,400 cm\(^3\). Now, we can find the number of moles (n) of the gas using the following formula:

\[n = \frac{Volume\, of\, Gas}{Molar\, Volume\, at\, s.t.p}\]

Substituting the given values, we get:

\[n = \frac{250\, cm^3}{22,400\, cm^3}\]

This simplifies to:

\[n = 0.01116\, mol\]

Now, to find the relative molecular mass (M) of the gas, we can use the formula:

\[M = \frac{Mass\, of\, Gas}{Number\, of\, Moles}\]

Substituting the given values, we get:

\[M = \frac{0.79\, g}{0.01116\, mol}\]

This simplifies to:

\[M \approx 71\]

Therefore, the relative molecular mass of the gas is approximately 71, which corresponds toOption D.

Correct Answer: A. is not equally deformed

Correct Answer: B. Preserve Life

Correct Answer: D. entrepreneurship

Correct Answer: A. catharsis

Correct Answer: D. The rates of the forward and products have been formed

Explanation

The correct answer is D.

Here's why:

• A. All the reactants have been used up. This describes a reaction that has gone to completion, which is not characteristic of equilibrium in a *reversible* reaction. At equilibrium, both reactants and products are present.

• B. All the products have been formed. Similar to A, this describes a complete reaction.

• C. There is no further change in temperature. While temperature is constant at equilibrium in an isolated system, this isn't the fundamental definition of equilibrium. The definition lies in the rates of the reactions.

• D. The rates of the forward and reverse reactions are equal. This is the defining characteristic of a dynamic equilibrium in a reversible reaction. At this point, reactants are still forming products, and products are still forming reactants, but these processes occur at the same rate, resulting in no *net* change in the concentrations of reactants and products.

*(Note: The option D seems to have a slight typo or truncation. It should be The rates of the forward and reverse reactions are equal.)*

Correct Answer: C. \(\frac{3x - 1}{ x(1 - x)}\)

Explanation

\(\frac{2}{1 - x} - \frac{1}{x}\) = \(\frac{2x - 1(1 - x)}{x(1 - x)}\)

= \(\frac{2x - 1(1 + x)}{x(1 - x)}\)

= \(\frac{3x - 1}{x(1 - x)}\)

Correct Answer: D. \(\frac{1}{2}\)