The property of calcium chloride which makes it useful as a drying agent is that it is
- A. ionic
- B. deliquescent
- C. a strong electrolyte
- D. a normal salt
If the solubility of KHCO3 is 0.40 mole dm-3 at room temperature , calculate the mass of KHCO3 in 100dm3 of the solution at this temperature. [KHCO3 = 100hmol
- A. 4.0g
- B. 10.0g
- C. 40.0g
- D. 100.0g
Which of the following compounds dissolves in water to form a solution with pH below 7?
- A. Sodium tetraoxosulphate (VI)
- B. Potassium hydroxide
- C. Ammonium chloride
- D. Sodium trioxocarbonate (IV)
Which of the following is an acid salt?
- A. NH4CI
- B. MgSO4 7H2O
- C. CH3COONa
- D. NaHCO3
An exothermic reaction is one which involves
- A. attainment of dynamic equilibrium
- B. loss of heat to the surrounding
- C. evolution of gas as it proceeds
- D. positive change in value of enthalpy
30cm3 pf hydrogen at s.t.p combine with 20cm3 of oxygen to form steam according to the following equation 2H2(g) + O2(g) → 2H2O(g).
Calculate the total volume of the gaseous mixture at the end of the reaction
- A. 50cm3
- B. 35cm3
- C. 30cm3
- D. 25cm3
Helium is preferred to hydrogen in filling balloons because hydrogen
- A. is inflammable
- B. is diatomic
- C. exhibits isotopy
- D. is a component of water
What volume of hydrogen is produced at s.t.p. When 2.60 g of zinc reacts with excess HCI according to the following equation? Zn(s) + 2HCI(aq) → ZnCI 2(aq) + H2(g) [Zn = 65; 1 mole of a gas occupies 22.4dm3 at s.t.p]
- A. 0.040dm 3
- B. 0.896dm 3
- C. 5.82dm 3
- D. 8.62dm 3
Gas molecules are said to be perfectly elastic because
- A. they collide without loss of energy
- B. they move about in straight lines
- C. the distances between them are negligible
- D. the volume occupied by them is negligible
Equal volumes of CO2 cnd CO at s.t.p have the same
- A. mass
- B. density
- C. rate of diffusion
- D. number of molecules
Which of the following movements can be described as random motion?
- A. wheelbarrow being pushed
- B. car travelling on a straight line
- C. Gas molecules colliding in a flask
- D. Planets going round the sun
Exhaust fumes discharged from a smoky vehicle gradually become invisible as a result of
- A. diffusion
- B. combustion
- C. absorption
- D. emission
One mole of a compound M(HCO3)2 has a mass of 162g. Calculate the relative atomic mass of M. [H = 1, C =12, O = 16]
- A. 122
- B. 101
- C. 53
- D. 40
If an element with high electron affinity combines with another element with low ionization energy the bond formed will be mainly
- A. covalent
- B. ionic
- C. dative
- D. metallic
Which of the following compounds has the highest ionic character?
- A. PCI5
- B. SiCI4
- C. AICI3
- D. KCI
The crystal layers in graphite are held together by
- A. electrostatic forces
- B. van der Waals' forces
- C. hydrogen bonds
- D. covalent bonds
Which of the following halogens is the most reactive?
- A. F2
- B. Br2
- C. l2
- D. Cl
Which of the following reactions is not feasible?
- A. Cl2 + 2Kl → 2KCI + I2
- B. Cl2 + 2NaF → 2NaCI + F2
- C. Zn + CuCI2 ZnCl2 + Cu
- D. Zn + 2AgNO3 → Zn(NO3)2 + 2Ag
In the Periodic Table, the elements that loss electrons most readily belong to
- A. Group 1 A
- B. Group 11 A
- C. Group 111 A
- D. Group V11 A
Which of the following properties increases down a group in the Periodic Table?
- A. Atomic radius
- B. Electronegativity
- C. Electon affinity
- D. Ionization energy
Calcium atom ionizes by
- A. gaining two electrons
- B. losing two electrons
- C. sharing two electrons
- D. gaining two protons