What is the concentration of a stock solution if 20 mL was used to make 400 mL of a 1.44
1 answer:
Given :
Volume of stock solution, .
Volume of diluted solution, .
Molarity of diluted solution, .
To Find :
The concentration of the stock solution.
Solution :
We know, dilution factor is given by :
....1)
and ....2)
Putting volume in above equation, we get :
D.F = 400/20
D.F = 20
Putting value of D.F in equation 2) we get :
The concentration of stock solution is nearest to 30 M.
Therefore, the correct option is 1) 30 M.
You might be interested in
Answer:
The required hybridization for a central atom that have:
a tetrahedral arrangement of electron pairs is
a trigonal planar arrangement of electron pairs is
a linear arrangement of electron pairs is
Explanation:
From the given information:
The required hybridization for a central atom that have:
a tetrahedral arrangement of electron pairs is
a trigonal planar arrangement of electron pairs is
a linear arrangement of electron pairs is
Hybridization is the mixing and blending of two or more pure atomic orbitals ( s, p and d) to forma two or more hybrid atomic orbitals that are identical in shape and energy e. sp ,sp² , sp³, sp³d hybrid orbitals.
Examples:
Tetrahedral
In CH₄ , carbon C is the central atom.
A 2s electron is excited from the ground state of boron 1s²2s²2p² to one of the empty orbitals to 2p to give the excited state 1s²2s²2p³.
In the excited state of carbon, the 2-s orbital can be mixed with the 2p orbitals in three ways : sp³, sp² and sp hybridization. For the formation of four sp³ hybrid orbitals, the 2s orbital are mixed with all the three p orbitals. The four sp³ hybrid orbitals are tetrahedrally arranged with a bond angle of 109.5⁰
Trigonal Planar
In BF₃ , Boron B is the central atom
A 2s electron is excited from the ground state of boron 1s²2s²2p¹ to one of the empty orbitals to 2p. The 2s orbital is then mixed with two orbitals of 2p to form three sp² hybrid orbitals that are trigonal planar arranged in the plane in order to minimize repulsion. They bonds between them form an equal strength and with bond angles of 120⁰
Linear arrangement:
In BeCl₂, Be is the central atom
To provide the unpaired electrons for covalent bonds a 2s electron is excited to a 2p orbital. Thereafter, the two atomic orbitals hybridize to give two identical orbitals called sp hybrid orbitals. The sigma bond for,ed are equal in bond lengths and form a bond angle of 180°