Physical changes occur when the properties of a substance are retained and/or the materials can be recovered after the change. Chemical changes involve the formation of a new substance. Formation of a gas, solid, light, or heat are possible evidence of chemical change.
Answer:
The K sp Value is 
Explanation:
From the question we are told that
The of 
is = 122.5 g/ mol
The mass of dissolved is 
The volume of solution is 
The number of moles of is mathematically evaluated as
Substituting values
Generally concentration is mathematically represented as
For
The dissociation reaction of is
The solubility product constant is mathematically represented as
Since there is no ionic reactant we have
![K_{sp} = [k^+] [ClO_3^-]](https://tex.z-dn.net/?f=K_%7Bsp%7D%20%3D%20%5Bk%5E%2B%5D%20%5BClO_3%5E-%5D)
First convert the amount of grams you have of each substance to moles. Find your limiting reactant by calculating how many grams are needed to complete this reaction. If done correctly, you would see that we need .226 moles of Potassium to complete this reaction. However, we only have .118 moles of Potassium, so K must be our limiting reactant. Then use the moles of K to find out how many moles of K^2S are made. Then convert the amount of moles of K^2S to grams and you should get 10.3 g K^2S
1. Answer is ₉₂²³⁵U<span>
<span>Since this is an alpha emission the atomic number
of the daughter nucleus decreases by 2 while mass number decreases by 4 compared to
parent atom. Since parent atom has 94 as atomic number the daughter atom should
have </span>94 - 2 = 92 as atomic number<span> <span>and </span></span>239 - 4 = 235 as mass
number. <span>
</span></span>₉₄²³⁹Pu → ₂⁴He + ₉₂²³⁵U<span>
2. </span><span>Answer is </span>₉₁²³⁴Pa<span>
</span><span>Since this is a beta emission, a neutron is
converted into a proton while emitting an electron. Hence atomic number
increases by 1 compared to mass number but mass number remains as same. Hence,
the </span>atomic number of the
daughter atom<span> <span>should be </span></span>90 + 1 = 91<span> <span>which belongs to </span></span>Pa<span>. But the </span>mass number is same
as 234.<span>
</span>₉₀²³⁴Th → ₋₁⁰e + ₉₁²³⁴Pa<span>
</span><span>
3.<span> <span>Answer is </span></span></span>₈¹⁸O<span>
</span><span>Since this is a positron emission, a proton is converted into a neutron
while emitting an positron. Hence atomic number decreases by 1 compared to mass
number but mass number remains as same. Hence, the </span>atomic number of the
daughter atom<span> should be </span>9- 1
= 8 <span>which belong to </span>O<span>. But the </span>mass
number is same as 18.<span>
</span>₉¹⁸F → ₊₁⁰e + ₈¹⁸O<span>
4. </span>Answer is ₈₀²⁰¹Hg<span>
</span><span>This is an </span><span>electron capture
decay. </span>A<span> proton is converted into a neutron by emitting
a gamma ray. In this process </span>mass number remains
as same<span> <span>as parent atom which is </span></span>201<span>, but the </span>atomic number is
decreased by 1<span> <span>than parent atom. Hence atomic number of
daughter nucleus is 81 -1 = </span></span>80 <span>which belongs to </span>Hg.<span>
</span><span>
</span>₈₁²⁰¹Tl + ₋₁⁰e → ₀⁰γ + ₈₀<span>²⁰¹Hg</span>
When the concentration is expressed in molality, it is expressed in moles of solute per kilogram of solvent. Since we are given the mass of the solvent, which is water, we can compute for the moles of solute NaNO3.
0.5 m = x mol NaNO3/0.5 kg water
x = 0.25 mol NaNO3
Since the molar mass of NaNO3 is 85 g/mol, the mass is
0.25 mol * 85 g/mol = 21.25 grams NaNO3 needed
