Hypotheisis is just like an initial building block for a building. The true statements about hypothesis among the given are-
- First guess- hypothesis is a proposed explanation for something which is observed. Thus the explanation is just a guess and not a proved one.
- An initial idea which is assumed to be true - The whole experiment or research is based on an assumption which is supposed to be true and the scientist works to prove that true.
Mole ratio:
MgCl₂ + 2 KOH = Mg(OH)₂ + 2 KCl
2 moles KOH ---------------- 1 mole Mg(OH)₂
moles KOH ------------------- 4 moles Mg(OH₂)
moles KOH = 4 x 2 / 1
= 8 moles of KOH
molar mass KOH = 56 g/mol
mass of KOH = n x mm
mass of KOH = 8 x 56
= 448 g of KOH
hope this helps!
Answer : The percent by mass of the solution is 7.81 %
Explanation : Given,
Mass of NaCl = 8.75 g
Mass of solution = 112.0 g
Now we have to determine the percent by mass of the solution.

Putting values in above equation, we get:

Therefore, the percent by mass of the solution is 7.81 %
Answer:
Group 18, also known as the Noble Gasses
Explanation:
Atoms strive for full stability by gaining or losing electrons to get 8 valence electrons in their valence shell, but Group 18 already has 8 electrons in their valence shell, and are therefore already stable in their ground state.