Answer:
Mass = 88.12 g
Explanation:
Given data:
Mass of iron oxide = 126 g
Mass of iron formed = ?
Solution:
Chemical equation:
Fe₂O₃ + 3CO → 2Fe + 3CO₂
Number of moles of iron oxide:
Number of moles = mass/molar mass
Number of moles = 126 g/ 159.69 g/mol
Number of moles = 0.789 mol
Now we will compare the moles of iron with iron oxide.
Fe₂O₃ : Fe
1 : 2
0.789 : 2/1×0.789 = 1.578 mol
Mass of iron:
Mass = number of moles ×molar mass
Mass = 1.578 mol × 55.84 g/mol
Mass = 88.12 g
Answer:
B. 3+
Explanation:
When Fe²⁺ loses an electron, it becomes an Fe³⁺ ion.
The loss of an electron in an atom makes the atom becomes positively charged. Further losing electrons makes the atom more positive.
For the given ion;
Fe²⁺ if it loses an electron more, it becomes Fe³⁺.
The expression is given as:
Fe²⁺ → Fe³⁺ + e⁻
Answer:
29.92grams of PbSO4
Explanation:
lead (iV) oxide = PbO2 = Molar mass: 239.2 g/mol
lead (ll) sulfate = PbSO4 = Molar mass: 303.26 g/mol
PbO2 = PbSO4
1:1 ratio
Pb = Lead
Lead has an oxidation number of 4+
O = Oxygen
Oxygen has an oxidation number of 2-
PbO2 + 4H+ + SO4 2- + 2e- = PbSO4(s) + 2H2O
Ok so the above would be the likely complete reaction, though we don't really need this as we already know the ratio is 1:1.
23.6g of PbO2
23.6/239.2 = 0.09866 Moles of PbO2
Since we have a 1:1 ratio we know that the same number of moles of PbSO4 are produced and since we know the molar mass it's simply molar mass multiplied by number of moles.
303.26 x 0.09866 = 29.92grams of PbSO4
The density of the liquid is about 1.85 g/mL.
Density is mass/volume. The volume is given (45.2 mL). The mass must be found by subtracting the tare weight of the graduated cylinder from the total:
95.1 g- 11.4g = 83.7g
Using the mass and volume of the liquid, you can now calculate the density:
d = m/v = 83.7g/45.2 mL = 1.8517699115 g/mL.
Of the original values, the least number of significant figures are 3, so the answer must have a degree of accuracy of 3 significant figures:
1.8517699115 g/mL ≈ 1.85 g/mL.
They are conductors because since they move freely around in metals it creates energy which will act as a conductor
