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 answer is the third one
The molar mass of O2 is 32g/mol. So the mol amount of these O2 is 56/32=2 mol. STP stands for the standard temperature and pressure which means the temperature is 0 ℃ and pressure is 100 kPa. And the molar volume of gas is 22.7 L/mol under STP. So the answer is 22.7*2=45.4 L
Answer:
Neutralization
Explanation:
When an acid react with base it form the salt and water. The reaction is also called neutralization reaction because both neutralize each other.
In neutralization reaction equal amount of acid and base react to neutralize each other and equal amount of water and salt are formed. When pH does not reach to 7 its means there is less amount of one of reactant which is not fully neutralize.
Neutralization reactions are also used as first aid. For example when someone is dealing with HCl for cleaning purpose of toilet and get touched. It is advised to neutralize it with soap, milk or egg white.
Example:
Hydrochloric acid when react with the sodium hydroxide, a salt sodium chloride and water are formed.
Chemical equation:
HCl + NaOH → NaCl + H₂O
Titration:
Neutralization reactions are also used to determine the concentration of solution. Titration is a quantitative technique in which acid or base is gradually added into the solution whose concentration is to be determine until the neutral point is reached.
Sodium, Atomic mass: 22.989769 g
You can see in a periodic table
