The estimated digit is dependent on the least count of the instrument being used. If the least count is 0.1 and the reading is between two divisions of the least count, then the estimated digit will be in the tenths, or 0.1 place. In this case, the estimated digit is 3, meaning the least count is 0.001.
Answer: A. The extra electrons start to fill higher sublevels in the energy level.
Explanation:
The answer is C. Because you need the sun to start your cycle which starts with water evaporation
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
We can use a variety of formulas to determine our answers here.
Our formula for pOH is -log(mol), and we can plug it in as -log(0.010). Take note that OH- is a base, not an acid.
So, the pOH of OH- is 2.
To find pH we can set up this simple equation:
pH + pOH = 14
All we need to do is subtract 2 from 14, therefore the pH is 12.
This makes sense since acids range in the pH of 1-6, and we are dealing with a base. Hope I could help!
