Answer:
d = 14.9 g/mL
Explanation:
Given data:
Mass of metal = 22.4 g
Volume of eater = 3.2 mL
Volume of water + metal = 4.7 mL
Density of metal = ?
Solution:
Volume of metal:
Volume of metal = volume of water+ metal - volume of water
Volume of metal = 4.7 mL - 3.2 mL
Volume of metal = 1.5 mL
Density of metal:
d = m/v
d = 22.4 g/ 1.5 mL
d = 14.9 g/mL
Answer:
0.0693M Fe
Explanation:
It is possible to quantify Fe in a sample using Mn as internal standard using response factor formula:
F = A(analyte)×C(std) / A(std)×C(analyte) <em>(1)</em>
Where A is area of analyte and std, and C is concentration.
Replacing with first values:
F = 1.05×2.00mg/mL / 1.00×2.50mg/mL
<em>F = 0.84</em>
In the unknown solution, concentration of Mn is:
13.5mg/mL × (1.00mL/6.00mL) = <em>2.25 mg Mn/mL</em>
Replacing in (1) with absorbances values and F value:
0.84 = 0.185×2.25mg/mL / 0.128×C(analyte)
C(analyte) = <em>3.87 mg Fe / mL</em>
As molarity is moles of solute (Fe) per liter of solution:
= <em>0.0693M Fe</em>
The two reason behind the invalidity of flame test are false positive and false negative.
while performing the flame test you must have to be accurate otherwise you will get false results may be positive for some element or may be negative in case the element is present. The main reason to get the false positive and false negative is the presence and contamination of sodium.
Because if they are submerged in the solvent, they would dissolve! This would prevent them from seperating and not allow you to actually record anything