UNIZIK Chemistry 2015/2016 Day 3 Past Questions

Practice each question, then open it to see the full details.

The postulate of Dalton's atomic theory which still holds is that

A.atoms can neither be created nor destroyed
B.the particles of the same clement are exactly alike
C.particles of different elements combine in a simple whole number ratio
D.all elements are made of small indivisible particles.

Hydrogen is readily released when dilute hydrochloric acid reacts with

A.Cu
B.Na
C.Au
D.Ag

What amount of mercury would be liberated if the same quantity of electricity that liberate 0.65g of zinc is applied?

A.2.10g
B.1.00g
C.4.02g
D.8.04g

When dissolved in water, NaOH flakes show

A.an endothermic change
B.an exothermic change
C.a slow reaction
D.a rapid reaction

P_(g) + G_(g) <--->3R_(s) + S_(g), ∆H is negative. Which of the following will increase the yield of R?

A.Using a larger closed vessel
B.Increasing the temperature
C.Removing some S
D.Adding a positive catalyst.

An example of a hygroscopic substance is

A.CuO_(s)
B.MgCl_2(s)
C.CaCl_2(s)
D.NaOH_(s)

In recharging a lead-acid accumulator, the reaction at the cathode can be represented as

A.Pb²⁺_(aq) + SO^2-_4(aq) --> PbSO_4(s)
B.Pb²⁺_(aq) + 2e^- --> Pb_(s)
C.Pb²⁺_(aq) + 2H₂O_(l) ---> PbO_2(s) + 4H⁺_(aq) + 4e^-
D.Pb_(s) ---> Pb²⁺_(aq) + 2e^-

Which of these pairs are synthetic and natural macromolecules respectively?

A.Haemoglobin and nylon, creatine and polyethylene
B.Nylon and polyethylene, creatine and haemoglobin
C.Nylon and creatine, polyethylene and haemoglobin
D.Polyethylene and creatine, nylon and haemoglobin

2SO_2(g) + O_2(g) <---> 2SO_3(g).
In the chemical reaction above, the substance that will increase the rate of production of sulphur (VI) oxide is

A.manganese (IV) oxide
B.finely divide iron
C.vanadium (V) oxide
D.nickel

When sodium dioxonitrate (III) (NaNO₂) dissolves in Water, ∆H is positive. The process of dissolution, is

A.exothermic
B.endothermic
C.isothermal
D.isomeric