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Answer:
Assign oxidation numbers to all atoms in the equation.
Compare oxidation numbers from the reactant side to the product side of the equation.
The element oxidized is the one whose oxidation number increased.
Explanation:
Answer:
1) 1.235 g.
2) 0.61 g.
Explanation:
- From the balanced equation:
<em>Al(OH)₃ + 3HCl → AlCl₃ + 3H₂O.</em>
1.0 mol of Al(OH)₃ reacts with 3.0 moles of HCl to produce 1.0 mol of AlCl₃ and 3.0 moles of H₂O.
<em>1) How many grams of HCl can a tablet with 0.880 g of Al(OH)₃ consume? </em>
- To calculate the amount of HCl needed to consume 0.880 g of Al(OH)₃, we need to calculate the no. of moles of Al(OH)₃:
no. of moles of Al(OH)₃ = mass/molar mass = (0.880 g)/(78.0 g/mol) = 1.13 x 10⁻² mol.
∵ Every 1.0 mol of Al(OH)₃ needs 3.0 moles of HCl to be consumed.
∴ 1.13 x 10⁻² mol of Al(OH)₃ needs (3 x 1.13 x 10⁻² = 3.385 x 10⁻² mol) of HCl.
The no. of grams of HCl = no. of moles of HCl x molar mass of HCl = (3.385 x 10⁻² mol)(36.5 g/mol) = 1.235 g.
<em>2) How much H₂O?</em>
∵ Every 1.0 mol of Al(OH)₃ produces 3.0 moles of H₂O.
∴ 1.13 x 10⁻² mol of Al(OH)₃ produces (3 x 1.13 x 10⁻² = 3.385 x 10⁻² mol) of H₂O.
<em>The no. of grams of H₂O = no. of moles of H₂O x molar mass of H₂O </em>= (3.385 x 10⁻² mol)(18.0 g/mol) = <em>0.6092 g ≅ 0.61 g.</em>
Answer:
E = 12.92 × 10^(-16) J
Explanation:
Formula for energy is;
E = hc/λ
Where;
h is Planck's constant = 6.63 x 10^(-34) J.s
c is speed of light = 3 × 10^(8) m/s
λ is wavelength = 0.154 nm = 0.154 × 10^(-9) m
E = (6.63 x 10^(-34) × 3 × 10^(8))/(0.154 × 10^(-9))
E = 12.92 × 10^(-16) J
