The gas is NH₃.
H₂ doesn't dissolve readily in water, SO₂ gives an acidic solution in water.
The solid residue is Fe(OH)₂.
FeSO₄ and Na₂SO₄ are soluble in water.
The answer is C.
The answer is (2) Copper. Because copper is consist of atom. If it is decomposed, the atom will be changed. While chemical change is just the break down and form of chemical bonds between atoms.
Answer:
B and C
Explanation:
When we have to do a buffer solution we always have to choose the reaction that has the <u>pKa closer to the desired pH value</u>. When we find the pKa values we will obtain:
![pKa_1=-Log[6.9x10^-^3]=2.16](https://tex.z-dn.net/?f=pKa_1%3D-Log%5B6.9x10%5E-%5E3%5D%3D2.16)
![pKa_2=-Log[6.2x10^-^8]=7.20](https://tex.z-dn.net/?f=pKa_2%3D-Log%5B6.2x10%5E-%5E8%5D%3D7.20)
![pKa_3=-Log[4.8x10^-^13]=12.31](https://tex.z-dn.net/?f=pKa_3%3D-Log%5B4.8x10%5E-%5E13%5D%3D12.31)
The closer value is pKa2 with a value of 7.2. Therefore we have to use the second reaction. In which 
is the <u>acid</u> and 
is the <u>base</u>. Therefore the answer for the first question is B and the answer for the second question is C.
Answer:
199920J
Explanation:
Given parameters:
Mass of steam = 85g
Unknown:
Heat released when the liquid is condensed = ?
Solution:
The heat released by the substance is given as;
H = mL
H is the heat released
m is the mass
L is the latent heat of steam = 2352J/g
Heat released = 85 x 2352 = 199920J
