Which of the following describes the chemical property of acids?
- A. None of the above
- B. Acid + XCO\(_3\) \(\to\) Salt + H\(_2\)O + NH\(_3\)
- C. Acid + NaOH \(\to\) Normal salt + CO\(_2\)
- D. Acid + X\(_n\)CO\(_3\) \(\to\) Salt + H\(_2\)O + CO\(_2\)
Which of the following pollutants will lead to the depletion of ozone layer?
- A. chlorofluorocarbon
- B. carbon (ii) oxide
- C. hydrogen sulphide
- D. sulphur (iv) oxide
Which two gases can be used for the demonstration of the fountain experiment?
- A. SO\(_4\) and NH\(_3\)
- B. SO\(_3\) and NH\(_3\)
- C. HCl and NH\(_3\)
- D. SO\(_2\) and CO
A radioactive nucleus has a half-life of 20 years, starting with 100,000 particles, how many particles will be left exactly at the end of 40 years
- A. 75,000 particles
- B. 35,000 particles
- C. 25,000 particles
- D. 50,000 particles
Na\(_2\)CO\(_3\) + 2HCl \(\to\) 2NaCl + H\(_2\)O + CO\(_2\)
The indicator most suitable for this reaction should have a pH equal to
- A. 5
- B. 7
- C. 3
- D. 9
The molecular shape and bond angle of water are respectively
- A. linear, 180°
- B. bent, 109.5°
- C. tetrahedral, 109.5°
- D. bent, 105°
Which of the following properties increases from left to right along the period but decreases down the group in the Periodic Table?
i. Atomic Number ii. Ionization energy iii. Metallic character iv. Electron affinity
- A. ii and iii only
- B. ii and iv only
- C. iii and iv only
- D. i and ii only
At 27°C, 58.5g of sodium chloride is present in 250cm\(^3\) of a solution. The solubility of sodium chloride at this temperature is?
(molar mass of sodium chloride = 111.0gmol\(^{-1}\))
- A. 2.0 moldm\(^{-3}\)
- B. 0.25 moldm\(^{-3}\)
- C. 1.0 moldm\(^{-3}\)
- D. 0.5 moldm\(^{-3}\)
What technique is suitable for separating a binary solution of potassium chloride and potassium trioxochlorate (V)?
- A. Fractional crystallization
- B. Fractional distillation
- C. Filtration
- D. Evaporation
Which of the following does not support the fact that air is a mixture?
- A. the constituents of air are in a fixed proportion by mass
- B. it cannot be represented with a chemical formula
- C. the constituents of air can be separated by physical by physical means
- D. none of the above
Which of the following statements about catalyst is false?
- A. biological catalysts are called enzymes
- B. catalyst do not appear in the balanced equation
- C. catalyst reduce the activation energy for a reaction
- D. catalysts do not alter the mechanism of the reaction and never appear in the rate low
The heat of formation of ethene, C\(_2\)H\(_4\) is 50 kJmol\(^{-1}\), and that of ethane, C\(_2\)H\(_6\) is -82kJmol\(^{-1}\). Calculate the heat evolved in the process:
C\(_2\)H\(_4\) + H\(_2\) \(\to\) C\(_2\)H\(_6\)
- A. -122kJ
- B. -132kJ
- C. -88kJ
- D. -60kJ
If acidified Potassium Dichromate(VI) (K\(_2\)Cr\(_2\)O\(_7\)) acts as oxidizing agent, color changes from
- A. yellow to green
- B. orange to green
- C. yellow to red
- D. orange to red
Which of the following reactions is an oxidation process?
- A. 2H\(^+\) + 2e\(^-\) \(\to\) H\(_2\)
- B. 2O\(^{2-}\) + 4e\(^-\) \(\to\) O\(_2\)
- C. OCl\(^-\) + H\(_2\)O + 2e\(^-\) \(\to\) 2OH\(^-\) + Cl\(^-\)
- D. Cl + e\(^-\) \(\to\) Cl\(^-\)
For the general equation of the nature
xP + yQ ⇌ mR + nS, the expression for the equilibrium constant is
- A. k[P]\(^x\)[Q]\(^y\)
- B. \(\frac{m[R][S]}{x[P]y[Q]}\)
- C. \(\frac{[P]^x[Q]^y}{[R]^m[S]^n}\)
- D. \(\frac{[R]^m[S]^n}{[P]^x[Q]^y}\)
Consider the reaction
A\(_{(s)}\) + 2B\(_{(g)}\) → 2C\(_{(aq)}\) + D\(_{(g)}\)
What will be the effect of a decrease in pressure on the reaction?
- A. the equilibrium will shift
- B. rate of forward reaction will increase
- C. rate of backward reaction will increase
- D. rates of forward and backward reaction are not affected
Which of the following represents the kind of bonding present in ammonium chloride?
- A. ionic only
- B. covalent only
- C. ionic and covalent
- D. dative covalent
When ammonia and hydrogen ion bond together to form ammonium ion, the bond formed is called
- A. electrovalent bond
- B. compound bond
- C. ionic bond
- D. covalent bond
The combustion of carbon(ii)oxide in oxygen can be represented by equation.
2CO + O\(_2\) → 2CO\(_2\)
Calculate the volume of the resulting mixture at the end of the reaction if 50cm\(_3\) of carbon(ii)oxide was exploded in 100cm\(_3\) of oxygen
- A. 75cm\(^3\)
- B. 125cm\(^3\)
- C. 100cm\(^3\)
- D. 50cm\(^3\)
By what amount must the temperature of 200cm\(^3\) of Nitrogen at 27°C be increased to double the pressure if the final volume is 150cm\(^3\) (Assume ideality)
- A. 150°C
- B. 177°C
- C. 75°C
- D. 120°C
Elements X and Y have electronic configurations 1s\(^2\)2s\(^2\)2p\(^4\) and 1s\(^2\)2s\(^2\)2p\(^6\)3s\(^2\)3p\(^1\) respectively. When they combine, the formula of the compound formed is
- A. XY
- B. X\(_2\)Y
- C. Y\(_2\)X\(_3\)
- D. X\(_2\)Y\(_3\)