Answer:
When zinc is added to copper sulphate (CUSO4) solution due to more reactivity of zinc, cooper is replaced by the zinc and forms zinc sulphate. During the process, the colour of the solution changes from blue to colourless.
Avogadro's number is the number of atoms in one mole of a substance. The number is 6.022 x 10^23 atoms/mol. So, if you have 1 mole of carbon atoms, there will be 6.022 x 10^23 atoms in that sample.
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22.4 molecules are in 4.48 liters of CO 2
26. a megagram = 10⁶ grams while a kilogram = 10³ grams, so the megagram is bigger
28. a mililiter = 10⁻³ liters while a microliter = 10⁻⁶ liters, so the mililiter is bigger
36. 1 meter is equal to 100 centimeters, so the decimal moves right 2 places
37. 1 micrometer is equal to 0.001 milimeters, so the decimal moves left 3 places
38. 1 centimeter is equal to 0.00001 kilometers, so the decimal moves left 5 places
39. 1 micrometer is equal to 10⁻¹² megameters, so the decimal moves left 12 places
40. 1 kilometer is equal to 100000 centimeters, so the decimal moves right 5 places