Year 10 - Chemistsry - 4.11.13

Thai Sikh International School

E-Learning Programme – Online Assignment –  29/10/2013

Name :                                                                                                                Subject : Chemistry

Year   :  10                                                                                                                 Week  No. :  3                                   

1. Find empirical formulas for the compounds containing the following percentages of each element. Use these atomic weights: Li=7 Br=80 K=39 S=32 Mg=24 C=12 O=16 Ca=40 Sc=45

a.     8.04 percent lithium, 91.96 percent bromide

b.      b. 70.9 percent potassium, 29.1 percent sulfur

c.       c. 28.6 percent magnesium, 14.3 percent carbon, 57.1 percent oxygen

d.      d. 29.4 percent calcium, 23.5 percent sulfur, 47.1 percent oxygen

e.      e. 65.2 percent scandium, 34.8 percent oxygen

f.        f. 42.9 percent carbon, 57.1 percent oxygen