First we calculate the concentration of HCl:
Moles = mass / Mr
= 25 / 36.5
= 0.685 mol
Concentration = 0.685/1.5 = 0.457 mol / dm³
For a strong monoprotic acid, the concentration of hydrogen ions is equal to the acid concentration.
pH = -log[H+]
pH = -log(0.457)
= 0.34
Answer:
C.
Explanation:
The electronic configuration of N (7 electrons): 1s² 2s² 2p³.
The orbital 1s is filled with two electrons and their spinning direction is opposite and also electrons of 2s.
3p contains (3 electrons) should fill the 3 orbitals firstly. Every orbital contains 1 electron and be in the same spin direction.
So, the right choice is c.
A is wrong because 2 electrons of 3p are paired in the first orbital before filling every orbital.
B is wrong because the 2 electrons of 1s and 2s are in the same direction and also 2 electrons of 3p are paired in the first orbital before filling every orbital.
D is also wrong the 2 electrons of 1s and 2s are in the same direction and the electron in the second orbital of 3p are in opposite direction of the other 2 electrons.
Answer:
Density of aluminum is 2.699 g/cm^3
Explanation:
Density of a given material can be defined as the mass of the substance present in a unit volume. Mathematically it can be expressed as:
Units: g/cm^3 or kg/m^3
Aluminum (Al) is one the lightest element and is known to have a density of 2.699 g/cm^3
Answer: the correct option is A (A zero net force causes no change to an object's
motion.)
Explanation:
Force is a vector quantity that causes an object to accelerate or change velocity when pushed or pulled. While a NET FORCE can be defined as the combination of all forces acting on an object which is equally capable of accelerating the object.
When a NET FORCE is equal to zero( that is zero net force),there will be no change to an object's motion. When the net force of an object is equal to zero , it shows the object is in either static equilibrium( the objects velocity is zero) or dynamic equilibrium(where the object is moving at constant velocity). In both cases, the object remains motionless because the net forces is equal to zero.
