ABU Chemistry 2019/2020 Past Questions

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

Elements P has an atomic number of 12 while element Q has an atomic number 15. Combination of P and Q gave a compound P_mQ_n. the respective values of m and n are

A.2 and 2
B.2 and 3
C.3 and 2
D.2 and 1

A solution of sodium trioxocarbonate(IV)contains 10.6g in 250cm³ of soluttion. Calculate the concentration of the solution.[${Na_2CO_3 = 106.0}$]

A.0.4moldm^-3
B.1.0moldm^-3
C.10.6moldm^-3
D.25.0moldm^-3

The shape of the water molecule is

A.linear
B.pyramidal
C.tetrahedral
D.V-shaped

The pH of four solutions W, X, Y, Z are 4, 6, 8, 10, respectively, therefore

A.none of the solutions is acidic
B.the pH of Y is made more acidic by addition of distilled water
C.Z is the most acidic solution
D.W is the most acidic solution
E.X is neutral

The process of converting start to ethanol is known as

A.distillation
B.cracking
C.fermentation
D.oxidation
E.hydrolysis

What is the solubility of a salt X at 25°C if the saturated solution of the salt contains 0.28g in 100cm³ of solution? [X = 56.0g]

A.0.05 moldm^-3
B.0.10 moldm^-3
C.2.60 moldm^-3
D.2.80 moldm^-3

The oxidation state of calcium in CaCl₂ is __________

A.+1
B.+2
C.+3
D.+4

When air, which contains the gases: oxygen, nitrogen, carbon dioxide, water vapour and the rare gases, is passed through alkaline pyrogallol and then over quicklime, the only gases left are

A.nitrogen and carbon dixodie
B.the rare gases
C.nitrogen and oxygen
D.nitrogen and the rare gases
E.nitrogen, carbon dioxide and the rare gases

What mass of water is produced when 8.0g of hydrogen reacts with excess oxygen?
(H = 1, O = 16)

A.36.0g
B.8.0g
C.72.0g
D.16.0g

All the following will liberate a gas when reacted with dilute hydrochloric acid except

A.Sodium trioxosulphate (IV) salt
B.Sodium trioxocarbonate (IV) salt
C.Sodium sulphide
D.Sodium trioxonitrate (V)