Which element, represented by X, reacts with fluorine to produce the compound XF2?

Answer:

The answer to your question is: letter A

Explanation:

A. Gas particles are in constant motion. This statement is true because this theory says that Gases are composed of a large number of particles that behave like hard, spherical objects in a state of constant, random motion.

B. Gas particles attract each other. This statement is false because this theory says that there is no force of attraction between gas particles or between the particles and the walls of the container.

C. Gas particles lose their energy during collisions. This statement is false, this theory says that none of the energy of a gas particle is lost when it collides with another particle or with the walls of the container.

D. Gas particles stick to the walls of their container. This statement is false, the theory says that there is no force of attraction between gas particles or between the particles and the walls of the container.

Answer: 181 kJ

Explanation:

The balanced chemical reaction is;

To calculate the moles, we use the equation:

According to stoichiometry:

1 mole of on complete combustion give= 555 kJ

Thus 0.326 moles of on complete combustion give=

Thus the enthalpy change for combustion of 15.0 g of ethanol is 181 kJ

Answer:

The final solution will be clear and colorless.

Explanation:

The balanced reaction equation is:

NaOH + HCl ⇒ H₂O + NaCl

The amount of NaOH that is added is calculated as follows:

(20.0mL)(1.0mol/L) = 20 mmol NaOH

Similarly, the amount of HCl that is added is as follows:

(10.0mL)(1.0mol/L) = 10 mmol HCl

Since HCl and NaOH react in 1:1 proportions, the HCl is the limiting reaction. 10 mmmol of HCl will neutralize 10 mmol of NaOH, leaving 10 mmol of NaOH. The volume of the mixed solution is 30.0 mL, so the concentration of NaOH in the final solution is:

(10 mmol)/(30.0mL) = 0.3333 M NaOH

The pOH of the final solution is:

pOH = -log([OH⁻) = -log(0.3333) = 0.477

The pOH is related to the pH as follows:

pH = 14 - pOH = 14 - 0.477 = 13.5

At a pH of 13.5, phenolphthalein is colorless. The final solution will be observed as clear and colorless.