4Fe(s) + 3O2(g) → 2Fe2O3(s) ....... ΔH = -1.7 x 10^3 kJ
<span>shows that 1700 kJ of heat is released when 4 moles of Fe react. </span>
<span>Molar mass of Fe = 56 g/mol </span>
<span>Molar mass of Fe2O3 = 160 g/mol. </span>
<span>(a) When 4 mol ( 4 x 56 = 224 g) iron reacted 1700 kJ are released, </span>
<span>when 9.0 g Fe reacted, the amount of energy will be </span>
<span>(9.0 x 1700) / (224) = 68.3 kJ </span>
<span>(b) According to the equation, 1700 kJ of energy released during the formation of 2 moles of Fe2O3 which is 2 x 160 = 320 g of rust. </span>
<span>120 kcal x (4.18 kJ / 1 kcal) = 501.6 kJ </span>
<span>When 1700 kJ released = 320 g rust </span>
<span>when 501.6 kJ released = (501.6 x 320) / 1700 = 94.4 g rust</span>
B. False. It is banned worldwide for agricultural uses. The <span>use of DDT is still authorized in small proportions in countries that need it, with support deployed for the alteration to safer and more effective alternatives.</span>
All organic material has decaying Carbon-14 in it. But if plants and animals are still alive, they constantly replace the supply of Carbon in their systems so the amount of Carbon 14 in the system stays constant. Once a plant or animal dies, the Carbon is no longer regenerated and so the Carbon 14 starts to decay.
Wdym mole like the animal or something else ?