1. Find the number of protons, neutrons, and electrons for : (a) 2H; (b) 235U; (c) 238U; (d) 13C;
2. Write empirical formulas for:(a) C6H12O6; (b) B2F6; (c) N2O4;
3. Name these compounds: (a) KClO4; (b) CaCO3; (c) NaHCO3; (d) MgSO3; (e) LiH2PO4; (f) HF (in water); (f) HI (in water);
4. Write formulas for: (a) iron (II) nitrate; (b) calcium hypochlorite; (c) sodium chlorate; (d) potassium perchlorate; (e) sodium bicarbonate; (f) lithium cyanide; (g) sodium permanganate; (h) hydrogen sulfide; (i) sodium sulfite; (j) sodium bisulfite;
5. How many atoms are there in 5.023 g of Sn?
6. How many molecule are there in a mole of H2? How many atoms?
7. Methane is CH4. Find the percent C and the percent H (by mass).
8. Silver chloride is AgCl. Find the percent Ag and the percent Cl (by mass).
9. Convert these temperatures to kelvin: (a) 113 ºC; (b) 37 ºC; (c) 357 ºC; (d) -11.5 ºC; (e) 6300 ºC
10. Convert these temperatures to Celsius: (a) 77 K; (b) 0 K; (c) 298 K; (d) 98.6 ºF (e) 212 ºF (f) 75 ºF
11. Express in scientific notation: (a) π ; (b) 12345.67; (c) 4 500 000 000 years; (d) 0.0000453; (e) 1; (f) 0.0000004004;
12. How many significant digits are in: (a) π ; (b) 100.0; (c) 100; (d) 1 000 000; (e) 100. ; (f) 2.345 × 1015 ;
13. Convert: (a) 123.4 kg to mg; (b) 123.4 mg to kg; (c) 45.9 pm to m; (d) 376.2 mm to km; (e) 342.7 cm to nm; (f) 0.143 Kg to g.
14. Find the following densities in g/cm3 AND kg/m3: (a) block weighing 17.2 g, with volume 4.03 cm3; (b) block weighing 76.2 g, with volume 22.03 cm3; (c) block weighing 143.2 g, with volume 7.03 cm3;
15. What are: (a) electron; (b) neutron; (c) proton; (d) α particle.
16. Balance the equations: (a) C + O2 → O; (b) H2 + N2 → NH3 (c) Cl2 + NaI → NaCl + I2;
17. We have a reaction Si + 2Cl2 → SiCl4. If we start with 50 g of Cl2, how much SiCl4 will we make (in grams) ?
18. We have a reaction 2NO + O2 → 2NO2. If we start with 0.886 moles of NO, and 0.503 moles of O2, whcih is the limiting reagent? How many moles of NO2 will we make ?
19. We have a reaction MnO2 + 4HCl → MnCl2 + Cl2 + 2H2O. If we start with 0.86 moles of MnO2 and 48.2 grams of HCl, which is the limiting reagent? How much grams of Cl2 will we make ?
20. The theoretical yield for a reaction is 91.192 g. The actual yield was 76.5 g. What is the percent yield?
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