We may use the molecular formula of the compound to determine the number of oxygen atoms in one formula unit. The formula unit is:
Mg(NO₃)₂
Here, we can see that there are two nitrate ions in each mole, and each mole of nitrate ion contains three oxygen atoms. Thus, there are 6 oxygen atoms in each formula unit of magnesium nitrate.
Density = Mass / Volume
V = 1.00 * 4.00 * 2.50 = 10 cm³
22.57 g/cm³ = Mass / 10 cm³
M = 22.57 g/cm³ * 10 cm³
M = 225.7 g
Answer: The mass of the block of osmium is 225.7 g.
The atom is krypton and its symbol is Kr.
the mass number is 41 + 36 = 77
its charge is 0 as it is a noble gas.
1)
a)
D = 0.79 g/cm³ m = 85.1 g
D = m / V
0.79 = 85.1 / V
V = 85.1 / 0.79 => 107.72 cm³
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b) D = m / V
0.79 = m / 125
m = 0.79 x 125 => 98.75 g
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hope this helps!
