<span>% by mass = mass solute x 100 / mass solution
45.5 % = mass solute NaF x 100 / 34.2
mass solute NaF = 34.2 x 45.5 /100=15.6 g
molae solute NaF = 15.6 g ( 1 mol / 41.9887 g)= 0.372</span>
This question may only be ansewered by frequent mattrrs
Answer:
Ca
2+
<K + <Ar<Cl − <S 2−
Explanation:
Ar,K +
,Cl −
,S 2−
,Ca 2+
have the same number of electrons. Their radii would be different because of their different nuclear charges. The cation with the greater positive charge will have a smaller radius because of the greater attraction of the electrons to the nucleus. Anion with the greater negative charge will have the larger radius. In this case, the net repulsion of the electrons will outweigh the nuclear charge and the ion will expand in size. Hence the correct order will be Ca
2+ <K + <Ar<Cl − <S 2−
Methyl orange shows red color in acidic medium and yellow color in basic medium. Because it changes color at the pKa of a mid strength acid, it is usually used in titration for acids. Unlike a universal indicator, methyl orange does not have a full spectrum of color change, but it has a sharp end point.
