Answer:
Specific rotation = -258°
Optical purity = 200%
Explanation:
Substances that have a chiral carbon ( a carbon which has four different atoms or compounds bond to it) have optical isomers. The different molecules are called enantiomers, and they differ by the side they deflect polarised light. A mixture contained the same number of the enantiomers is not optical and doesn't deflect polarized light. It's called a racemic mixture.
The specific rotation (spec.rot.) can be calculated by the equation:
spec.rot. = α/lc
Where α is the observed rotation of the plane polarised light in degrees, l is the path length in decimeters, and c is the concentration of the solution in g/100 mL.
The initial concentration is 10g/500mL = 2g/100 mL. The racemic mixture doesn't change the specific rotation, so the final concentration is 10g/1000 mL = 1g/100 mL. Then:
with α and l the same:
spec.rot.1/spec.rot.2 = c2/c1
spec.rot.2 = c1xspec.rot.1/c2
spec.rot.2 = 2x(-129°)/1
spec.rot.2 = -258°
If for a -129° the optical purity was 100%:
-129° ---------- 100%
-258° --------- x
By a direct simple three rule:
129x = 25800
x = 200%
6.02 times 10 to the 23rd power
Explanation:
It is known that atoms that have same number of valence electrons will show similar chemical properties.
So, when we move from left to right across a period there occurs increase in number of valence electrons of each element. But when we move down a group then number of valence electrons remain the same.
Hence, elements of same group will show similar chemical properties.
Therefore, we can conclude that elements marked as 2 and 3 will have similar chemical properties.
Answer:
Explanation:
Physical properties and physical change:
Physical properties are the properties of substance that do not involve the change in to another matter while the process through which change is happen is called physical change.
For example,
Melting point is physical property and the process "melting" is called physical change.
Freezing point is physical property and the process "freezing" is called physical change.
Chemical property and chemical change:
Chemical property is the ability of substance to change into another substance while the process through through which it is happen is called chemical change or chemical reaction.
For example:
The chemical property of iron is to react with oxygen and form rust. This process or chemical change is called corrosion. So corrosion is chemical change.
Hydrocarbon react with oxygen and form water and carbon dioxide. It is the chemical property. While the process is called combustion so combustion is a chemical change.
Answer:
it's a river flowing into the sea
Explanation:
i had it on a quiz for k12 on god it's the good one have a good day
