A. sulfur dioxide ...................................................
Explanation:
Atomic size is defined as the distance between the nucleus and valence shell of an atom. Valence shell is the outermost shell of an atom.
When we move across a period in a periodic table then there will occur a decrease in atomic size of the atoms. But when we move across a group in a periodic table then there will occur an increase in atomic size of the atom.
Hydrogen is a period 1 element, oxygen is a period 2 element, chlorine is a period 3 element and bromine is a period 4 element.
Therefore, given elements are arranged in order of increasing atomic size as follows.
H < O < Cl < Br
Answer:
14.8 g/mol
Explanation:
Starting on the left, count in 3 numbers (14.8), then round using the next number (0.02).
Because 2 is less than 5, the number stays the same and is not rounded up.
Answer : The mass of 
is, 4.43 grams.
Explanation :
As we know that, when dissolve in water then it dissociates to give 2 mole of sodium ion 
and 1 mole of sulfate ion 
The chemical reaction will be:
Thus, the concentration of = 
First we have to calculate the moles of
Now we have to calculate the mass of
Molar mass of = 142 g/mol
Thus, the mass of is, 4.43 grams.
Answer:
c. I, II and III
Explanation:
The cell is as follows
Cr / Cr⁺²(1M) // H⁺ ( 1 M ) / H₂
Standard reduction potential of hydrogen cell is zero . Standard reduction potential is negative E for Cr⁺² / Cr(1M) half cell
Cell potential = Ecathode - Eanode
= 0 - ( - E)
= E
E is cell potential and also standard cell potential or emf of the cell .
Standard reduction potential that is for Cr3+/Cr. is - E .
Hence statement I , II , III are right . IV th statement is wrong because of sign
Option c is correct.
