Answer:
+4
Explanation:
In PbO2, oxygen exhibits an oxidation number of -2 (since it's not a peroxide or superoxide):
Let the oxidation number of Pb be x. Then, for the compound to be neutral, the oxidation numbers of all atoms should add up to zero.
⇒ x + (−2) + (−2) = 0
x = +4
So the oxidation no. of Pb is +4.
I hope this helps.
To determine what gas is this, we use Graham's Law of Effusion where it relates the rates of effusion of gases and their molar masses. We do as follows:
r1/r2 = √(M2 / M1)
Let 1 be the the unkown gas and 2 the H2 gas.
r1/r2 = 0.225
M2 = 2.02 g/mol
0.225 = √(2.02 / M1)
M1 = 39.90 g/mol
From the periodic table of elements, most likely, the gas is argon.
Such ions are said to be isoelectronic
<h2>Answer:</h2>
2 hydrogen atoms.
<h2>Explanations:</h2>
Given the chemical formula H2SO4,
The compound shows that the formula has 4 atoms of oxygen, one atom of sulfur and 2 hydrogen atoms.
Therefore, the number of hydrogen atom in the molecule H2SO4 is 2 hydrogen atoms.
Answer:
0.0025g/cm³
Explanation:
Given parameters:
Mass of the brown sugar = 12.9g
dimension of the sugar = 8cm
unknown:
density of the sugar = ?
Solution
Density is defined as the mass per unit volume of a substance. The expression is given below:
Density = 
We know the mass of the substance but the volume is unknown:
Volume of the brown sugar = l x bx h = 8x8x8 = 512cm³
Density of the brown sugar = 
= 0.0025g/cm³
