The balanced equation between the
and
is:

Formula of molarity is:


Substituting the values,

So, number of moles of
is
.
From the balanced equation it is clear that for 1 mole of
, 2 moles of
are required.
Hence, 0.21 mole of
= 
Molar mass of
= 
So, the mass of
= 
Answer:
159.609 g/mol
Explanation:
According to the CuSO4.5H2O (k) heat CuSO4 (k) + 5 H2O (g) equation, the crystal water amount of copper sulfate and its rough formula will be calculated.
Weight of copper sulfate containing crystal water = m1 = 249.62… g
Weight of copper sulfate without crystal water weighed = m2 = 159.62 g
Accordingly, calculate the x and y values in the molecular formula of copper sulfate (xCuSO4.yH2O).
Answer:
i think its the first one
We use the gas law named Charle's law for the calculation of the second temperature. The law states that,
V₁T₂ = V₂T₁
Substituting the known values,
(0.456 L)(65 + 273.15) = (3.4 L)(T₁)
T₁ = 45.33 K
Unfortunately you did not specify the electronic configuration in the question, however since one of the answers must be a halogen, i took the liberty to attach an image with the configuration (both the simple numeric and spdf form) for all the halogen and all you have to do is match the electronic configuration you have in your question to the one in the table attached and you can then deduce the answer.
Hope this helps.