Answer:
1.22 x 10²⁵ molecules CO₂
Explanation:
To find the amount of molecules, you need to multiply the number of moles by Avogadro's Number. Avogadro's Number is a ratio which represents the amount of molecules per every 1 mole. It is important to arrange this ratio in a way that allows for the cancellation of units (since you are going from moles to molecules, moles should be in the denominator). The final answer should have 3 sig figs like the given value.
Avogadro's Number:
6.022 x 10²³ molecules = 1 mole
20.2 moles CO₂ 6.022 x 10²³ molecules
--------------------------- x -------------------------------------- = 1.22 x 10²⁵ molecules
1 mole
a) (NH4)2SO4 --- 1 mole of it contains 2 moles of N, 8 moles of H, 1 mole of S, and 4 moles of O.
MM = (2 moles N x 14.0 g/mole) + (8 moles H x 1.01 g/mole) + (1 mole S x 32.1 g/mole) + (4 moles O x 16.0 g/mole) = 132 g/mole.
6.60 g (NH4)2SO4 x (1 mole (NH4)2SO4 / 132 g (NH4)2SO4) = 0.0500 moles (NH4)2SO4
b) The molar mass for Ca(OH)2 = 74.0 g/mole, calculated like (NH4)2SO4 above.
4.5 kg Ca(OH)2 x (1000 g / 1 kg) x (1 mole Ca(OH)2 / 74.0 g Ca(OH)2) = 60.8 moles Ca(OH)2
Answer: Depending on the state of change it can be a physical change. Example: Evaporation is the physical change of a liquid turned into a gas.
That said, I'm pretty sure the answer is (True)
Note: Hope this is correct and it helps. Good luck :)
