Chemistry Answers

how would you relate alchemy to synthesis of new elements?

The method for removing toxins in cycad fruit that was used by the Aboriginal

and Torres Strait Islander Peoples was:

A) Burning the plant to ashes

B) Crushing the cycad into a powder

C) Roasting, crushing and then soaking in a bowl of water

D) Roasting, crushing and then leaching in a flowing river

Which of the following best describes the effect of a catalyst on the

equilibrium constant K and the rate of reaction?

A) Reaction rate increases in the forward direction and K increases

B) Reaction rate decreases in the reverse direction and K decreases

C) Reaction rate increases in both directions and K remains constant

D) Reaction rate decreases in both directions and K increases

Which of the following combinations forms a precipitate?

A) BaNO3(aq) + NH4OH(aq)

B) Mg(NO3)2(aq) + NaCl(aq)

C) CH3COOK(aq) + NaNO3(aq)

D) BaNO3(aq) + Na2SO4(aq)

( which is the correct answer )

For the reaction:

H2(g) + Br2(g) ⇌ 2HBr(g)

Which of the following best describes the effect of increased pressure on the

equilibrium constant K and rate of reaction?

A) Reaction rate increases in the forward direction and K increases

B) Reaction rate decreases in the forward direction and K decreases

C) Reaction rate increases in both directions and K remains constant

D) Reaction rate decreases in both directions and K increases

An equilibrium exists between NO2 and N2O4 in a gaseous system as

represented below:

2NO2(g) ⇌ N2O4(g)

NO2 (g) has an intense orange appearance whereas N2O4 (g) is colourless.

Heating this system at equilibrium increases the intensity of the orange colour.

From this information, the forward reaction would be classified as:

A) endothermic

B) exothermic

C) both exothermic and endothermic

D) neither exothermic nor endothermic

For the reaction in question (6), the value of the equilibrium constant

at 300K compared with that at 500K is:

A) Larger

B) The same

C) Smaller

D) Insufficient information for a comparison to be made

6. For the following reaction

N2 (g) + 3 H2 (g) 2NH3 (g) ∆𝐻𝐻 = −92𝑘𝑘𝑘𝑘

the equilibrium expression that is correct is:

( which is the correct answer)

The equilibrium constant for the reaction between gaseous hydrogen and

chlorine was found to be 5.7. Under the same conditions the equilibrium

constant for the reaction between gaseous hydrogen and fluorine was found

to be 18.4

From this information, it can be concluded that at equilibrium, under the same

conditions:

A) More HCl would form than HF

B) Less HCl would form than HF

C) The same amount of each would form

D) No such conclusions can be reached

( which one is the correct answer )

Comparing the solubility products of Mg(OH)2 and Ba(OH)2 (refer to data

sheet), the following conclusion can be made:

A) Magnesium hydroxide is more soluble than Barium hydroxide

B) Barium hydroxide is more soluble than Magnesium hydroxide

C) Hydroxides are all soluble

D) Hydroxides are all insoluble