WORK SHEET-CHAPTER-7
Study Check 7.1
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How many moles of water, H2O, contain 2.60 × 10 molecules of water?
Study Check 7.2
How many moles of aspirin, C9H8O4, contain 0.480 mol of O?
Study Check 7.3
Calculate the molar mass for salicylic acid, C7H6O3, which is used to treat skin
conditions such as acne, psoriasis, and dandruff.
Study Check 7.4
A dentist orders 24.4 g of gold (Au) to prepare dental crowns and fillings.
Calculate the number of moles of gold in the order.
Study Check 7.5
One tablet of an antacid contains 680. mg of CaCO3. How many moles of CaCO3
are present?
Study Check 7.6
Tin(II) fluoride (SnF2) is added to toothpaste to strengthen tooth enamel. How
many grams of tin(II) fluoride contain 1.46 g of F?
Study Check 7.7
Ethylene glycol, C2H6O2, used as automobile antifreeze, is a sweet-tasting liquid,
which is toxic to humans and animals. What is the mass percent composition of
ethylene glycol?
Study Check 7.8
Phosphine is a highly toxic compound used for pest and rodent control. If a sample
of phosphine contains 0.456 g of P and 0.0440 g of H, what is its empirical
formula?
Study Check 7.9
Sulfate of potash is the common name of a compound used in fertilizers to supply
potassium and sulfur. What is the empirical formula of this compound if it has a
mass percent composition of 44.9% K, 18.4% S, and 36.7% O?
Study Check 7.10
Glyoxylic acid is used by plants and bacteria to convert fats into glucose. What is
the empirical formula of glyoxylic acid if it has a mass percent composition of
32.5% C, 2.70% H, and 64.8% O?
Study Check 7.11
The insecticide lindane has a mass percent composition of 24.78% C, 2.08% H,
and 73.14% Cl. If its experimental molar mass is 290 g, what is the molecular
formula?