Calcium oxide (CaO) or lime in solid form can be prepared from the decomposition of calcium hydroxide {Ca in to lime (CaO) and water (
at high temperature. The reaction is an endothermic reaction. That is heat is absorbed in this reaction process. One mole of calcium hydroxide decomposed into one mole of calcium oxide and one mole of water. The balanced reaction can be shown as-CaC
(solid) → CaO (solid) +
(liquid). The heat of the reaction is (+) 63.7 kJ/mole of CaO.
5. 1.16 x moles moles of pennies would be required to equal the mass of the moon.
6. 12.86 moles of ethanol are in a 750 ml bottle of vodka.
Explanation:
5 .Data given:
mass of penny = 2.5 grams
atomic mass of penny = 62.93 grams/mole
moles present in mass of the moon given as = 7.3 x kg
number of moles =
number of moles =
0.039 moles of penny is present in 2.5 grams
0.039 moles of penny in 2.5 grams of it
so, x moles in 7.3 X grams
x = 1.16 x moles
so when the mass of the penny given is equal to the mass of moon, number of moles of penny present is 1.1 x .
6.
Given:
vodka = 40% ethanol
volume of vodka bottle = 750 ml
moles of ethanol =?
density of ethanol =0.79 g/ml
atomic mass of ethanol = 46.07 grams/mole
so, from the density of ethanol given we can calculate how much ethanol is present in the solution.
density =
density x volume = mass
0.79 x 750 = 592.5 grams
number of moles =
number of moles of ethanol =
= 12.86 moles of ethanol