<span>Which of the following lists characteristics of a lake and NOT a reservoir A. Artificial dam, fresh water B. natural dam, filled by runoff C. earth dam, salt water D. filled by erosion, cement dam
Answer is B: natural dam,filled by runoff</span>
Answer:
6.25 grams is the mass of solute dissolved.
Explanation:
w/w % : The percentage mass or fraction of mass of the of solute present in total mass of the solution.
Mass of the solution = 50.0 g
Mass of the solvent = x
w/w % = 12.5%
x = 6.25 g
6.25 grams is the mass of solute dissolved.
Answer:
Mass = 357.7 g
Explanation:
Given data:
Mass of Fe = 250 g
Mass of oxygen = 120 g
Mass of iron(III) oxide produced = ?
Solution:
Chemical equation:
4Fe + 3O₂ → 2Fe₂O₃
Number of moles of Fe:
Number of moles = mass/molar mass
Number of moles = 250 g/ 55.8 g/mol
Number of moles = 4.48 mol
Number of moles of O₂ :
Number of moles = mass/molar mass
Number of moles = 120 g/ 32 g/mol
Number of moles = 3.75 mol
Now we will compare the moles of reactants with product.
Fe : Fe₂O₃
4 : 2
4.48 : 2/4×4.48 = 2.24
O₂ : Fe₂O₃
3 : 2
3.75 : 2/3×3.75= 2.5
Less number of moles of Fe₂O₃ are produced by Fe thus it will act as limiting reactant.
Mass of Fe₂O₃:
Mass = number of moles × molar mass
Mass = 2.24 mol × 159.69 g/mol
Mass = 357.7 g
<h3>What is the oxidation number of oxygen in H2O?</h3>
Oxygen almost always has an oxidation number of -2, except in peroxides (H 2 O 2) where it is -1 and in compounds with fluorine (OF 2) where it is +2. Hydrogen has an oxidation number of +1 when combined with non-metals, but it has an oxidation number of -1 when combined with metals.
<h3><em>Sure hoep this helps you :)</em></h3>
