HARD
11th Maharashtra Board
IMPORTANT
Earn 100

Work out the percentage composition of constituent elements in the following compound:
Potassium dichromate (K2Cr2O7), 
Atomic mass: ( Pb=207; P=31; O=16; K=39; Cr 52; Na=23; N =14)

Important Questions on Introduction to Analytical Chemistry

HARD
11th Maharashtra Board
IMPORTANT
Chemistry>Chapter 2 - Introduction to Analytical Chemistry>Exercises>Q 4

Work out the percentage composition of constituent elements in the following compound:
 Microcosmic salt — Sodium ammonium hydrogen phosphate, tetrahydrate  (NaNH4 HPO4 .4H2 O)
(Atomic mass: Pb=207; P=31; O=16; K=39; Cr=52; Na=23; N=14)

HARD
11th Maharashtra Board
IMPORTANT
Chemistry>Chapter 2 - Introduction to Analytical Chemistry>Exercises>Q 4
Find the percentage composition of constituent green vitriol crystals (FeSO4 .7H2O).
Also, find out the mass of iron and the water of crystallization in 4.54 Kg of the crystals. Atomic mass: ( Fe=56; S=32; O=16)
HARD
11th Maharashtra Board
IMPORTANT
Chemistry>Chapter 2 - Introduction to Analytical Chemistry>Exercises>Q 4
The red colour of blood is due to a compound called “haemoglobin”. It contains 0.335 % of iron. Four atoms of iron are present in one molecule of haemoglobin. What is its molecular weight ? (Atomic mass: Fe 55.84)
HARD
11th Maharashtra Board
IMPORTANT
Chemistry>Chapter 2 - Introduction to Analytical Chemistry>Exercises>Q 4
A substance, on analysis, gave the following percent composition: Na=43.4 %, C=11.3 % and O=45.3 %. Calculate the empirical formula.
(Atomic mass: Na=23 u, C=12 u, O=16 u.)
HARD
11th Maharashtra Board
IMPORTANT
Chemistry>Chapter 2 - Introduction to Analytical Chemistry>Exercises>Q 4
Assuming the atomic weight of a metal M to be 56, find the empirical formula of its oxide containing 70.0% of M.
HARD
11th Maharashtra Board
IMPORTANT
Chemistry>Chapter 2 - Introduction to Analytical Chemistry>Exercises>Q 4
1.00 g of a hydrated salt contains 0.2014 g of iron 0.1153 g  of sulphur, 0.2301 g of oxygen and 0.4532 g of water of crystallisation. Find the empirical formula. (Atomic weight:  Fe=56; S=32; O=16)
HARD
11th Maharashtra Board
IMPORTANT
Chemistry>Chapter 2 - Introduction to Analytical Chemistry>Exercises>Q 4
An organic compound containing oxygen, carbon, hydrogen and nitrogen contains 20 % carbon, 6.7 % hydrogen and  46.67 % nitrogen. Its molecular mass was found to be 60. Find the molecular formula of the compound.
HARD
11th Maharashtra Board
IMPORTANT
Chemistry>Chapter 2 - Introduction to Analytical Chemistry>Exercises>Q 4
A compound on analysis gave the following percentage composition by mass : H=9.09; O=36.36; C=54.55. Molar mass of compound is 88. Find its molecular formula.