Answer:
54
Barium atomic number is 56, this means that it has 56 protons in its nucleus and put it as a period 6 element. an uncharged barium atom would have 56 electron also. However as a group 2 element barium easily loses 2 electron to form the +2 cation. the ions has 56-2=54
Answer: The initial temperature of the iron was 
Explanation:
As we know that,
![m_1\times c_1\times (T_{final}-T_1)=-[m_2\times c_2\times (T_{final}-T_2)]](https://tex.z-dn.net/?f=m_1%5Ctimes%20c_1%5Ctimes%20%28T_%7Bfinal%7D-T_1%29%3D-%5Bm_2%5Ctimes%20c_2%5Ctimes%20%28T_%7Bfinal%7D-T_2%29%5D)
.................(1)
where,
q = heat absorbed or released
= mass of iron = 360 g
= mass of water = 750 g
= final temperature = 
= temperature of iron = ?
= temperature of water = 
= specific heat of iron = 
= specific heat of water= 
Now put all the given values in equation (1), we get
![-360\times 0.450\times (46.7-x)=[750\times 4.184\times (46.7-22.5)]](https://tex.z-dn.net/?f=-360%5Ctimes%200.450%5Ctimes%20%2846.7-x%29%3D%5B750%5Ctimes%204.184%5Ctimes%20%2846.7-22.5%29%5D)
Therefore, the initial temperature of the iron was
Answer is: V<span>an't Hoff factor (i) for this solution is 2,26.
</span>Change in freezing point
from pure solvent to solution: ΔT =i · Kf · m.
<span>Kf - molal freezing-point depression constant for water is 1,86°C/m.
</span>m - molality, moles of solute per kilogram of solvent.
n(K₂SO₄) = 16,8 g ÷ 174,25 g/mol
n(K₂SO₄) = 0,096 mol.
m(K₂SO₄) = 0,096 mol/kg.
ΔT = 0,405°C.
i = 0,405 ÷ (1,86 · 0,096)
i = 2,26.
The Answer Is D I just Did The Quiz And It Said It Was Right
