Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.
The experiment that showed that atoms have tiny positively charged nucleus was first carried out by
Moseley
Rutherford
Millikan
Dalton
Correct answer is B
The experiment that showed that atoms have tiny positively charged nuclei was first carried out by Rutherford. Rutherford's gold foil experiment showed that the atom is mostly empty space with a tiny, dense, positively charged nucleus.
Diffusion is slowest in solid particles than in particles of liquid and gases because
solid particles have more kinetic energy than the particles of liquid and gases
solid particles have less kinetic energy than the particles of liqiud and gases
solid particles have less restriction in their movement than liquid and gas particles
the particles in solids are far apart and the cohesive forces between them are negligible
Correct answer is B
Diffusion is faster in gases owing to their higher kinetic energy i.e increase in kinetic energy of molecules leads to increase in rate of diffusion.
300 cm3 of gas has a pressure of 800 mmHg. If the pressure is reduced to 650 mmHg, find its volume
243.75 cm3
369.23 cm3
738.46 cm3
1733.36 cm3
Correct answer is B
P1V1= P2V2
800 * 300 = 650 * V2
V2 = (800 * 300)/650 = 369.23 cm3
22.40 dm3
11.20 dm3
2.24 dm3
1.12 dm3
Correct answer is C
2NaHCO3(s) → Na2CO3(s) + H2O(l) + CO2
Relative molecular mass of NaHCO3 = 23 +1 + 12 + 16 * 3 = 84gmol-1
2 * 84g of NaHCO3 will be liberated 22.4dm3 or CO2 at s.t.p
16.8g of NaHCO3 will liberate (16.8 * 22.4)/(2 * 84) = 2.24 dm3
0.40g
0.80g
4.00g
8.00g
Correct answer is C
2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)
Relative molecular mass of NaOH = 23 + 16 + 1 = 40smol-1
2 * 23g of sodium react with water to produce
2 * 40g of NaOH
∴ 2.3g of sodium will react with water to produce
(2.3 * 40 * 2)/(23 * 2) = 4.00g