Quiz11sec3

The following system is in equilibrium:

2S_(s) + 5F_{2 (g)} ⇌ SF_{4 (g)} + SF_{6 (g)}

The equilibrium will shift to the right if ………

• The concentration of SF₄ is increased

• the pressure on the system is increased

• the pressure on the system is decreased.

• The concentration of SF₆ is increased

When the mass of zinc and volume of acid are constant, the rate of the reaction between zinc …………… and …………… hydrochloric acid …………… is as high as possible.

• block / conc. / at 75˚C

• Powder / dil. / at 50˚C

• block / conc. / at 50˚C

• Powder / conc. / at 75˚C

For the reaction : A + B = C , when the concentration of reactants = concentration of products , this means:

• this reaction may reach to equilibrium state or not

• this reaction sure doesn’t reach to equilibrium state

• this reaction sure is a complete reaction

• this reaction sure is a complete reaction

Which of the following changes have the same effect on the reaction: 2HCl_(g) ⇌ 2H_2(g) + Cl_2(g) (∆H= +)

• Increasing pressure and temperature

• Increasing temperature and concentration of Cl₂

• Adding catalyst and increasing temperature

• Decreasing pressure and removing H₂ gas from the reaction medium

In the following equilibrium reaction:

N₂O_4(g) ⇌ 2NO_2(g) ∆H= +57.2KJ

The amount of NO₂ can be increased by……………….

• Adding catalyst

• Decreases the volume of vessel

• Removing N₂O₄

• Increasing temperature

2Hl_(g) + Cl_2(g) ⇌2HCl_(g) + l_2(g) + energy

A gaseous reaction occurs and comes to equilibrium as shown above Which of the following changes to the system will serve to increase the number of moles of l₂ present at equilibrium?

• All the previous

• Decreasing the temperature at constant volume.

• Increasing the volume at constant temperature.

• Increasing the temperature at constant volume

Given the reaction at equilibrium.

N_2(g) +3H_2(g)⇌2NH_3(g) + heat

Which change would shift the equilibrium to right?

• Increase of the pressure.

• Decrease of the hydrogen gas concentrations.

• Decrease of the nitrogen gas concentration.

• Increase of the temperature.

The reaction of dil. Hydrochloric acid with iron acid with iron filings is a complete reaction, because ……………

• The recombination of the produced hydrogen gas with iron (II) chloride is impossible

• it occurs at a high temperature.

• The reactants and products are in equilibrium state.

• it occurs under high pressure.

Which of these reactions leads to producing H₂ gas with slower rate? ……………

• Mg strip with HCl acid (2M).

• Mg strip with HCl acid (1M).

• Mg powder with HCl acid (1M).

• Mg powder with HCl acid (2M).

In the reaction:

Mg_(s) + 2HCl_(aq) → MgCl_2(aq) + H_2(g)

The reaction rate increase on adding more magnesium to the acid, this is due to ……

• increasing the reactants concentration.

• increasing the surface area of magnesium exposed to the reaction.

• acting of magnesium as an oxidizing agent.

• changing the nature of the reactants.