43
Neutral atoms of neon with atomic number 10 have the same number of electron as
- A. O2+
- B. Ca2+
- C. K+
- D. Mg2+
44
3Cu + pHNO3 →3Cu(NO)2 + 4H2 O + xNO
In the equation above, the values of p and x respectively are
- A. 1 and 3
- B. 2 and 3
- C. 6 and 2
- D. 8 and 2
45
The filter in the cigarette reduces the nicotine content by
- A. Burning
- B. Adsorption
- C. Evaporation
- D. Absorption
46
What is the percentage by mass of oxygen in Al2(SO4)3. 2H2O?
[Al = 27, S = 32, H = 1, O = 16]
- A. 14.29%
- B. 25.39%
- C. 50.79%
- D. 59.25%
47
Which of the following is physical change?
- A. Burning kerosene
- B. Freezing ice cream
- C. Exposing white phosphorus
- D. Dissolving calcium in water
48
What volume of oxygen is produced from the decomposition of 2 mole of KCIO3 at s.t.p?
[Molar volume of a gas at s.t.p = 22.4 dm3]
- A. 22.4 dm3
- B. 33.6 dm3
- C. 44.8 dm3
- D. 67.2 dm3