Answer:
Light years are the only practical unit for measuring the distance of space
Explanation:
Practical... aka logical.
Answer:
The number of molecules= 1.33 × 10∧22 molecules
percentage of mercury = 87%
Explanation:
Given data:
mass of dimethyl mercury = 5.10 g
number molecules of dimethyl mercury in 5.10 g = ?
percentage of mercury = ?
Solution:
First of all we will calculate the molar mass of dimethyl mercury.
molar mass of HgC2H6 = 1×200.6 + 2×12 + 6×1 = 230.6 g/mol
we know that,
230.6 g of HgC2H6 = 1 mol = 6.02 × 10∧23 molecules.
so
For the 5.10 g of sample:
5.10 g/230 g/mol = 0.022 moles of HgC2H6
now we will multiply these number of moles with Avogadro number to get number of molecules in 5.10 g of sample.
0.022 × 6.02 × 10∧23 molecules = 0.133 × 10∧23 molecules or
1.33 × 10∧22 molecules.
Percentage of mercury:
Formula:
percentage = (atomic number of Hg × total number of atoms of Hg/ molar mass of HgC2H6) × 100
% age of Hg = (200.6 g/mol× 1/ 230.6 g/mol) × 100
%age of Hg = 0.869 × 100
%age of Hg = 86.99 % or 87 %
They have the same density because a material, no matter how much of it there is, will always be a certain density. A 40g ball of iron has the same density as a 1g ball of iron.
<span>For a particular redox reaction ClO2– is oxidized to ClO4– and Fe3 is reduced to Fe2 . The balanced redox reaction is expressed as:
</span>
4OH-+ClO2- + 4Fe^3+ ---> ClO4- + 4Fe2+ + 2H2O
Hope this answers the question. Have a nice day.
Answer:
- Question 19: the three are molecular compounds.
Explanation:
<em>Question 19.</em>
All of them are the combination of two kinds of different atoms in fixed proportions.
- C₂H₄: two carbon atoms per four hydrogen atoms
- HF: one hydrogen atom per one fluorine atom
- H₂O₂: two hydrogen atoms per two oxygent atoms
Thus, they all meet the definition of compund: a pure substance formed by two or more different elements with a definite composition.
Molecular compounds are formed by covalent bonds and ionic compounds are formed by ionic bonds.
Two non-metal elements, like H-F, C - C, C - H, H-O, H - H, and O - O will share electrons forming covalent bonds to complete their valence shell. Thus, the three compounds are molecular and not ionic.
<em>Question 20. </em>Formula of copper(II) sulfate hydrate with 36.0% water.
Copper(II) sulfate is CuSO₄. Its molar mass is 159.609g/mol
Water is H₂O. Its molar mass is 18.015g/mol
Calling x the number of water molecules in the hydrate, the percentage of water is:
From which we can solve for x:
Thus, there are 5 molecules of water per each unit of CuSO₄, and the formula is: