Answer:
Ca generally loses two electrons from its outer shell to form a Ca2+ ion.
<span>26.833 liters
Aluminum oxide has a formula of Al</span>₂O₃,<span> which means for every mole of aluminum used, 1.5 moles of oxygen is required (3/2 = 1.5).
Given 42.5 g of aluminum divided by its atomic mass (26.9815385) gives 1.575 moles of aluminum.
Since it takes 1.5 moles of oxygen per mole of aluminum to make aluminum oxide, you'll need 2.363 moles of oxygen atoms.
Each molecule of oxygen gas has 2 oxygen atoms, so the moles of oxygen gas will be 2.363/2 = 1.1815
Finally, you need to calculate the volume of </span>1.1815 <span>moles of oxygen gas.
1 mole of gas at STP occupies 22.7 liters of volume. Therefore,
1.1815 * 22.7 = </span>26.8 liters <span>of oxygen gas.
</span>
<u>We are given:</u>
Mass of ice = 21 grams
The ice is already at 0°c, the temperature at which it melts to form water
Molar heat of fusion of Ice = 6.02 kJ/mol
<u>Finding the energy required:</u>
<u>Number of moles of Ice: </u>
Molar mass of water = 18 g/mol
Number of moles = given mass/ molar mass
Number of moles = 21 / 18 = 7/6 moles
<u>Energy required to melt the given amount of ice:</u>
Energy = number of moles * molar heat of fusion
Energy = (7/6) * (6.02)
Energy = 7.02 kJ OR 7020 joules
The chemical elements are arranged in order of increasing atomic number. Answer A.
Answer:
Note that melting and vaporization are endothermic processes in that they absorb or require energy, while freezing and condensation are exothermic process as they release energy.
