Calcium ions have oxidation state 2+ => Ca (2+).
Bromime ions (bromide) have oxidation state 1- => Br (-).
So, to be neutral the compound has to have two Br (-) ions per each Ca(2+) ion.
That is represented in the chemical formula as Ca Br2, where the number 2 to the right of Br is a subscript meaning that there are two atoms of Br per each atom of Ca (the lack of subscript means 1 atom).
Answer: Ca Br2.
Answer:
Mass of CuSO4.H2O obtained: 
Explanation:
The molecular weight of the salt is: 
<u>In the solution</u>: 12.5 g of CuSO4
In moles: 
<u>Mass of wate</u>r:
5 moles of water per mol of salt: 
Mass of CuSO4.H2O obtained: 
Answer:
A.0.20M
Explanation:
c 1 V 1 = c 2 V 2
Initial Volume, V1 = 200 mL
Final Volume, V2 = 200 + 400 = 600 mL
Initial Concentration, c1 = 0.60 M
Final Concentration, c2= ?
Solving for c2;
c2 = c1v1 / v2
c2 = 0.60 * 200 / 600
c2 = 0.20M
Answer: The value of
is 0.050.
Explanation:
According to Raoult's law, the vapor pressure of a component at a given temperature is equal to the mole fraction of that component multiplied by the vapor pressure of that component in the pure state.

As we know the mole fraction of
is 0.12
The partial pressure of 
The partial pressure of
Thus the partial pressure of
is = [3 - (0.36+0.720)] atm = 1.92 atm
= 1.92 atm




The value of
is 0.050.
Answer: 3.36 L of ammonia gas
Explanation:
The balanced chemical reaction is:
According to stoichiometry :
3 moles of
produce = 2 moles of
Thus 0.75 moles of
will producee=
of
But as percent yield is 30 %, amount of ammonia produced = 
According to ideal gas equation:
P = pressure = 1 atm
V = Volume = ?
n = number of moles = 0.15
R = gas constant =
T =temperature =
Thus 3.36 L of ammonia gas is obtained by reacting 0.75 moles of hydrogen with excess nitrogen.