Answer:
a. 211.7
Explanation:
Iron Pyrite reacts with Oxygen to produce Iron (II) Oxide and Sulphur (IV) Oxide.
The equation is as follows:
4FeS₂₍s₎ + 11O₂₍g₎ → 2Fe₂O₃₍s₎ + 8SO₂₍g₎
From the equation, 4 moles of FeS₂ produce 8 moles of SO₂.
Therefore the reaction ratio is 4:8 or 1:2
198.20 grams of FeS₂ into moles is calculated as follows:
Moles= Mass/RMM
RMM of FeS₂ is 119.9750g/mol.
Number of moles = 198.20/119.9750g/mol
=1.652 moles of FeS₂
The reaction ratio of FeS₂ to SO₂ produced is 1:2
Thus SO₂ produced = 1.652 moles×2/1=3.304 moles
The mass of SO₂ produced =Moles ×RMM
=3.304 moles ×64.0638 g/mol
=211.667 grams
=211.7g
In the physical properties, it is mentioned that the element has 4 valence electrons. The elements in the periodic table are arranged such that, the number of valence electrons present in the neutral atoms belonging to a particular group is equal to the group number.
Thus, the unidentified element can be best classified as a nonmetal in period 4
Ans C)
Answer:
starch: A soft white chemical made by all green plants. It’s a relatively long molecule made from linking together a lot of smaller, identical building blocks — all of them glucose, a simple sugar. Plants and animals use glucose as an energy source. Plants store that glucose, in the form of starch, as a reserve supply of energy.
Explanation:
1. C. Linus Pauling
2. C. chemistry
3. A. atom
4. D. protons, neutrons and electrons
5. B. positively
6. A. negatively
7. C. uncharged
8. D. carries a charge
9. C. Au
10. D. protons in the nucleus
11. A. atoms
12. B. the pull of gravity on matter
13. C. protons
14. C. 112
15. C. symbols
16. D. compounds
17. C. sodium chloride salt
18. C. solids, liquids, and gases
19. A. the gaseous state
20. C. a number and a unit
21. B. the weight of an object
22. D. 1,000
23. C. 100
24. B. uncertain
25. D. 4
26. A. 1
27.C. 2.26 x 102
28. C. 5 x 10-3
29. C. atomic number
30. A. 5 g/cm3
31. D. temperature
32. C. meter
33. B. 2.2
Answer:
Explanation:
Step 1: Given data
- Molarity of the HF solution (M): 0.500 M
- Volume of the solution (V): 750.0 mL
Step 2: Convert "V" to liters
We will use the conversion factor 1 L = 1000 mL.
750.0 mL × 1 L/1000 mL = 0.7500 L
Step 3: Calculate the moles of HF
We will use the following expression.
n = M × V
n = 0.500 mol/L × 0.7500 L = 0.375 mol
Step 4: Calculate the atoms of F in 0.375 moles of HF
We will use the following relationships:
- 1 mole of HF contains 1 mole of atoms of F.
- 1 mole of atoms of F contains 6.02 × 10²³ atoms of F (Avogadro's number).
