The following is the introduction to a special e-publication called Determining the Age of the Earth (click the link to see a table of contents). Published earlier this year, the collection draws articles from the archives of Scientific American. In the collection, this introduction appears with the title, “Stumbling Toward an Understanding of Geologic Timescales.”
Answer:
All cells have structural and functional similarities. Structures shared by all cells include a cell membrane, an aqueous cytosol, ribosomes, and genetic material (DNA). All cells are composed of the same four types of organic molecules: carbohydrates, lipids, nucleic acids, and proteins.
Explanation:
⊂_ヽ
＼＼ Λ＿Λ
＼( ˇωˇ)
> ⌒ヽ
/ へ＼
/ / ＼＼
ﾚ ノ ヽ_つ
/ / YOU GOT DAT
( (ヽ
| |、＼
| 丿 ＼ ⌒)
| | ) /
ノ ) Lﾉ
(_／
The molar mass of Na₂SO₄ -
2 x Na - 2 x23 = 46
1 x S - 1 x 32 = 32
4 x O - 4 x 16 = 64
total = 46 + 32 + 64 = 142 g/mol
the molarity of solution - 2.0 M
in 1 L of solution , 2.0 moles
Therefore in 2.5 L - 2 mol/L x 2.5 L = 5 mol
then the mass of Na₂SO₄ required = 142 g/mol x 5 mol = 710 g
Answer:
1 : 1
Explanation:
We know that the equation is balanced because the number of zinc, hydrogen, sulfur and oxygen atoms are the same in both sides of the equation.
Zn + H2SO4 → ZnSO4 + H2
We can see that there is one molecule for Zn and also one molecule for ZnSO4 (we know this because there are no numbers before the formulas, so the 1 is implied)
That is why the mole ratio of zinc to zinc sulfate is 1 : 1
