<span>Density is a value for
mass, such as kg, divided by a value for volume, such as m3. Density is a
physical property of a substance that represents the mass of that substance per
unit volume. We calculate as follows:
PV = nRT
PV = mRT/ Molar mass
m/V = P(molar mass)/RT
Density = P(molar mass)/RT
Density = 2.0 ( 30.97 ) / 0.08206 ( 20 + 273.15) = 2.57 g/L <----First option</span>
Answer:
In the criss-cross method, the numerical value of the ion charge of the two atoms are crossed over, which becomes the subscript of the other ion. Using this technique, we will write the chemical formula of the given compounds.
Criss cross the absolute values to give Al2O3. To find the formula for magnesium oxide:- The oxidation number of Mg is +2 and oxygen is -2. Criss cross the absolute values to give Mg2O2In this example there is a common factor of 2 so divide by 2 to give MgO.
The bond is polar covalent because the difference in electronegativity is greater than 0.4, but less than 1.7.
Electronegativity refers to the ability of an atom in a compound to attract the electrons of the bond towards itself. It is a periodic trend that increases across the period but decreases down the group.
The electronegativity difference between the two atoms as shown in the question is 1.55. This means that the bond is polar covalent because the difference in electronegativity is greater than 0.4, but less than 1.7.
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