Given :
A 10.99 g sample of NaBr contains 22.34% Na by mass.
To Find :
How many grams of sodium does a 9.77g sample of sodium bromine contain.
Solution :
By law of constant composition , in any given chemical compound, the elements always combine in the same proportion with each other.
Therefore , percentage of Na by mass in NaBr will be same for every amount .
Percentage of Na in 9.77 g NaBr is 22.34 % too .
Gram of Na = .
Hence , this is the required solution .
Answer:
The correct option is: e) n=4, l=3, = - 2 ,
= - 1/2
Explanation:
The four quantum numbers that describe the electrons in an atom are: The principal: n, azimuthal: l, magnetic: m, and spin: s.
For a given electron, the values of the quantum numbers should be in the <u>given range</u>- principal quantum number: n ≥ 1;
azimuthal quantum number: 0 ≤ l ≤ n − 1;
magnetic quantum number: −l ≤ ≤ +l;
spin quantum number: −s ≤ ≤ +s
Now, for n= 4,
The value of l: 0 to n − 1 = 0 to 3 = 0, 1, 2, 3
The value of for l= 3 : -3 to +3 = -3, -2, -1, 0, +1, +2, +3
The value of : -1/2, +1/2
<u>Therefore, the given set of quantum numbers</u>: n=4, l=3, = - 2 ,
= - 1/2; <u>are possible and permissible for an electron in an atom.</u>
Answer : The equilibrium concentration of will be, (C)
Explanation : Given,
Equilibrium constant = 14.5
Concentration of at equilibrium = 0.15 M
Concentration of at equilibrium = 0.36 M
The balanced equilibrium reaction is,
The expression of equilibrium constant for the reaction will be:
Now put all the values in this expression, we get:
Therefore, the equilibrium concentration of will be, (C)