We are given an equation 2Mg+O2-> 2MgO and a starting chemical Mg of about 212 g. In order to solve for the amount of O2 needed, we need the molecular weight of Mg and O2.
Molecular weight:
Mg=24.305 g/mol
O2=16(2)=32 g/mol
Note that for every 1 mol of O2, the amount of Mg must be 2 mol.
So,
g O2 = 212 g Mg x1mo Mgl/24.305 g Mg x1mol O2 /2 mol Mg x 32 g O2/mol O2
gO2=139.56 g
Therefore, 139.56 g of O2 is needed for every 212 g Mg.
Answer:
zero
Explanation:
In a unit cell, an atom that is located at the center of a cube edge is not involved in sharing unit cells because a central atom of a unit cell belongs to the entire cell and only to that unit cell of the lattice.
Hence, the center atom of a unit cell do not share any unit cell and the correct answer is "Zero".
1) period
2) the answer is D) I because they are in the same column
3) B)Ge because they are in the same column
4) A) Al because they are in the same column (share same characteristics)
5) D) they have the same number of valence electrons
6) D) nonmetals
Answer is: The breakdown of ozone is an endothermic process.
There
are two types of reaction: endothermic reaction (chemical reaction that
absorbs more energy than it releases) and exothermic reaction (chemical
reaction that releases more energy than it absorbs).
Ozone has lower energy than molecular oxygen (O₂) and oxygen atom, so ozone need energy to break bond between ohygen atoms.
Answer:
1. 0.74mol
2. 0.42mol
3. 2.125mol
4. 0.301mol
5. 4.52 × 10^23 particles
Explanation:
Number of moles (n) in a substance can be found using the formula:
mole (n) = mass/molar mass
Using this formula, the following moles are calculated:
1. Molar of Na = 23g/mol
mole = 17/23
mole = 0.74mol
2. Molar mass of Na2SO4 = 23(2) + 32 + 16(4)
= 46 + 32 + 64
= 142g/mol
Mole = 60/142
mole = 0.42mol
3. Molar mass of CO2 = 12 + 16(2)
= 12 + 32
= 44g/mol
mole = 93.5/44
mole = 2.125mol
4. Molar mass of sodium nitrate (NaNO3) = 23 + 14 + 16(3)
= 23 + 14 + 48
= 85g/mol
mole = 25.6/85
mole = 0.301mol
5. Number of particles in one mole of a substance is 6.022 × 10^23 particles. Hence, in 0.75mol of calcium hydroxide (Ca(OH)2, there will be;
0.75mol × 6.02 × 10^23
= 4.515 × 10^23
= 4.52 × 10^23 particles
