The second one, the third one, and the fourth one
Answer:
false, Potassium and fluorine are not halogens.
only fluorine here is halogen.
potassium is an alkali earth metal it doesn't comes under category of halogens, but fluorine
is a non metal which comes under halogen family.
Answer:
Is a substance that can maintain certain range of pH
Explanation:
A buffer is mixture of two salts that are complementary, one salt is acid and another is basic, but since then share some part of their structure, if you add to this mixture another acid, the basic salt can absorb it and still maintaining the same pH. If you pour a base, the acid salt will absorb it and again the final pH will remain the same. So the buffers are used to maintain the same pH does not matter if you add small quantities of an acid or base.
Basis: 1 L of the substance.
(1.202 g/mL) x (1000 mL) = 1202 g
mass solute = (1202 g) x 0.2 = 240.2 g
mass solvent = 1202 g x 0.8 = 961.6 g
moles KI = (240.2 g) x (1 mole / 166 g) = 1.45 moles
moles water = (961.6 g) x (1 mole / 18 g) = 53.42 moles
1. Molality = moles solute / kg solvent
= 1.45 moles / 0.9616 kg = 1.5 m
2. Molarity = moles solute / L solution
= 1.45 moles / 1 L solution = 1.45 M
3. molar mass = mole solute / total moles
= 1.45 moles / (1.45 moles + 53.42 moles) = 0.0264
