Answer:
1,Iodine solution is used to test leaves for the presence of starch. ...
2.After a few minutes, the parts of the leaf that contain starch turn the iodine from brown to blue/black.
3.The leaf on the left is a variegated leaf
Explanation:
Answer:
Explanation:
mole of NaOH present = molarity x volume
= 1.0 X 0.05 = 0.05 mole
<em>Recommended mole of HCl </em>= 1.1 x 0.05 = 0.055
<em>Mole of HCl carelessly added by Jacob </em>= 1.1 x 0.04 = 0.044
From the equation of reaction:
HCl + NaOH ----> NaCl + H2O
The ratio of mole of HCl to that of NaOH for a complete neutralization reaction is 1:1. However, the recommended mole of HCl (0.055 mole) is more than the mole of NaOH (0.05 mole). <u>Hence, the recommended endpoint of the reaction is supposed to be acidic.</u>
The mole of HCl added by Jacob (0.044) is short of the recommended amount (0.055) and also short of the amount required for a neutral endpoint (0.05). <u>This means that the endpoint will have an excess amount of NaOH and as such, basic instead of the desired acidic endpoint.</u>
Answer:
There are no acceptable descriptions at all on that list of choices.
Hey there!
The number of vacancies per unit volume => ( Nv = 2.3*10²⁵ m⁻³ )
Avogrado's number => ( NA = 6.022*10²³ atoms/mol )
Density of material ( p ) in g/m³ :
1 g/cm³ = 1000000 g/m³ so:
7.40 * ( 1000000 ) = 7.40*10⁶ g/m³
Atomic mass = 85.5 g/mol
* Calculate the number of atomic sites per unit volume :
N = NA * p / A
N = ( 6.022*10²³ ) * ( 7.40*10⁶ ) / 85.5
N = 4.45*10³⁰ / 85.5
N = 5.212*10²⁸ atoms/m³
Therefore:
Calculate the fraction of vacancies :
Fv = Nv / N
Fv = 2.3*10²⁵ / 5.212*10²⁸
FV = 4.441*10⁻⁴
Hope that helps!
