1 mole of h3bo3...........6.023*10²³ each h and B and 0 so we will have 3hydrogen+ 1 B+3 oxygen = 7*6.023*10²³ atoms
1 mole .......7*6.023*10²³atoms
4 moles ........x atoms
x=4*7*6.023*10²³.
Answer:
In a neutral molecule, the sum of the bonding valance electrons must be equal. So the products of the negative element and its charges and the positive element and its charge must be equal.
Explanation:
C1×N1 = C2×N2
If we have a 3 valance electrons , the 'A' charge will be either +3 or -5 for a full octet and valance electron in 'B' atoms will mostly result in acquisition of additional electrons (2) for an octet and relative charge of -2.
Balancing the two,
3 × A = -2 × B
To be equal, A = 2 and B = 3
Therefore, A²B³
The initial concentration of the unknown acid is 0.1900 M.
Explanation:
Titration is a chemical method of analysis to know the concentration and volume of the unknown chemical or analyte.
The formula for the titration is:
Macid x Vacid = Mbase x V base
The volume must be in litres. The volume is given in ml it should be divided with 1000 to obtain values in litre.
Data given are:
volume of acid= 10 ml 0.01 L
Molarity of the acid = ?
volume of the NaOH or base = 15.4 ml or 0.0154 L (equivalence point of the base)
molarity of the base = 0.1234 M
Applying the formula and putting the values, we get
Macid x 0.01 = 0.1234 x 0.0154
Macid = 0.1900 M
The weak acid is having molarity of 0.1900 M against the strong base with molarity of 0.1234M.
Answer:
339kJ
Explanation:
Given parameters:
Mass of steam = 150g = 0.15kg
Initial temperature of steam = 100°C
Final temperature of water = 100°C
Unknown:
Quantity of heat that must be removed to condense the steam = ?
Solution:
The heat involved here is a latent heat because there is no change temperature. The process is just a phase change.
H = mL
m is the mass
L is the latent heat of vaporization = 2,260 kJ/kg
Insert the parameters and solve;
H = 0.15kg x 2,260 kJ/kg
H = 339kJ
Answer:
Option B : burning of wood
Explanation:
Chemical change is a change where a new substance is created like when you will bur wood you get ash this is a new substance, so burning of wood is a chemical change.
