Answer: The oxidation state of selenium in SeO3 is +6
Explanation:
SeO3 is the chemical formula for selenium trioxide.
- The oxidation state of SeO3 = 0 (since it is stable and with no charge)
- the oxidation number of oxygen (O) IN SeO3 is -2
- the oxidation state of selenium in SeO3 = Z (let unknown value be Z)
Hence, SeO3 = 0
Z + (-2 x 3) = 0
Z + (-6) = 0
Z - 6 = 0
Z = 0 + 6
Z = +6
Thus, the oxidation state of selenium in SeO3 is +6
First, find percent of oxygen: atom/molecule... there are 2 atoms of Oxygen so: O2/C2H2O2 which is: 32g O2 / 58g C2H2O2 =32/58.
<span>Next, multiply this by the total mass (56g C2H2O2) and the units will cancel out (g*g/g -> g) leaving you with the mass of Oxygen: </span>
<span>56g C2H2O2 * 32g O2/58g C2H2O2 = 56*32/58= 31g</span>
Answer:

Explanation:
You must calculate the moles of CaCl₂, then convert to formula units of CaCl₂.
1. Molar mass of CaCl₂
CaCl₂ = 40.08 + 2×35.45 = 40.08 + 70.90 = 110.98 g/mol
2. Moles of CaCl₂

3. Formula units of CaCl₂

Answer:
1.373 wt% Ca(OH)₂
Explanation:
Sample mix = 15.0g
Ca(OH)₂(aq) + 2HCl(aq) => CaCl₂(aq) + 2H₂O(l)
moles HCl = 0.2000g / 36 g·mol⁻¹ 0.0056 mol
moles Ca(OH)₂ = 1/2(moles HCl) = 1/2(0.0056 mol) = 0.0028 mol
mass Ca(OH)₂ = 0.0028 mol ( 74 g/mol ) = 0.206 g
mass % Ca(OH)₂ = (0.206/15.0)100% = 1.373 wt%