Fil in the blanks
a. The mass of 1 molecule of water `(H_(2) O)` is ………
b. The number of molecules in `16 g` of sulphur dioxide `(SO_(2))` are ……….
c. The weight of one mole of sodium carbonate `(Na_(2) CO_(3))` is……………..
d. Moles and g equivalent in `196 g` of `Ca (OH)_(2)` are ...... and .......
e. Moles and `g` equivalent in `196 g` of `H_(3) PO_(4)` are ............. and ............
f. `g` atoms in `62 g` of `P_(4)` are .......
f. `g` atoms in `24 g` of magnesium are...........

Answer

A, B, C, D

Explanation

a. `(18)/(6.023 xx 10^(23)) = 3.0 xx 10^(-23)`
b. `n_(SO_(2)) = (16)/(64) = (1)/(4)`
Number of molecules `= (1)/(4) xx 6.023 xx 10^(23) = 1.5 xx 10^(23)`
c. `Na_(2) CO_(3) = 2 xx 23 + 12 + 3 xx 16 = 106 g`
d. `n_(Ca(OH)_(2)) = (196)/(74) = 2.648, ~~ 2.65`
`Eq_(Ca(OH)_(2)) = 2.65 xx 2 = 5.3` (valency factor = 2)
e. `n_(H_(3)PO_(4)) = (196)/(98) = 2, Eq = 2 xx 3` (tribasic acid) = 6
f. `g` atom or mol `= (62)/(31 xx 4) = 0.5`
g. `g` atom or mol `= (24)/(24) = 1`