CHEMISTRY QUESTIONS AND ANSWER

1.       Calculate the number of moles of H 2 SO 4 in 50 cm 3 of a 0.50 moldm -3 solution. 2.       Calculate the number of moles of FeSO 4 in 25 cm 3 of a 0.2 moldm -3 solution. 3.       Calculate the mass of KMnO 4 in 25 cm 3 of a 0.02 moldm -3 solution. 4.       Calculate the mass of Pb(NO 3 ) 2 in 30 cm 3 of a 0.1 moldm -3 solution. 5.       What is the molarity of 1.06g of H 2 SO 4 in 250 cm 3 of solution? 6.       What is the molarity of 15.0 g of CuSO 4 .5H 2 O in 250 cm 3 of solution? 7.       What volume of a 0.833 moldm -3 solution of H 2 O 2 will be required to make 250 cm 3 of a 0.100 moldm -3 solution? 8.       What volume of a 0.50 moldm -3 solution of HCl will be required to make 100 cm 3 of a 0.050M solution? 9. ...

1.2 Exercise 1 – Avogadro’s Number and reacting masses 1. Calculate the number of moles present in each of the following cases: 2. Calculate the mass of substance present in the following cases: 3. Calculate the relative molecular mass of the following substances and suggest a possible identity of each substance: a) 2.3 g of Na a) 0.05 moles of Cl 2 a) 0.015 moles, 0.42 g b) 2.5 g of O 2 b) 0.125 moles of KBr b) 0.0125 moles, 0.50 g c) 240 kg of CO 2 c) 0.075 moles of Ca(OH) 2 c) 0.55 moles, 88 g d) 12.5 g of Al(OH) 3 d) 250 moles of Fe 2 O 3 d) 2.25 moles, 63 g e) 5.2 g of PbO 2 e) 0.02 moles of Al 2 (SO 4 ) 3 e) 0.00125 moles, 0.312 g 4. Calculate the number of particles in the following substances: a) 0.025 moles             b) 2.5 g of CO 2 ...

1.1 exercise 1 - atomic symbols Deduce the number of protons, neutrons and electrons in the following species: 1.       1 1 H 2.       17 8 O 3.       4 2 He 2+ 4.       132 54 Xe 5.   27 13 Al 3+ 6.   235 92 U 7.   1 1 H + 8.   45 21 Sc 3+ 9.   37 17 Cl - 10. 14 6 C Use the periodic table to write symbols for the following species: 11. 19 protons, 20 neutrons, 18 electrons 12. 8 protons, 8 neutrons, 10 electrons 13. 1 proton, 2 neutrons, 1 electron 14. 82 protons, 126 neutrons, 80 electrons 15. 53 protons, 74 neutrons, 54 electrons   1.1 EXERCISE 2 – ram, rmm and mass spectra Deduce the relative atomic masses of the following elements. 1.         Silicon ( 28 Si 92.21%, 29 Si 4.70%, 30 Si 3.09%) 2.   Silv...