A compound of bromine and fluorine is used to make UF6, which is an important chemical in processing and reprocessing of nuclear fuel. The compound contains 58.37% by mass of bromine. Determine its empirical formula.
Magnesium reacts with iron(III) chloride to from magnesium chloride(which can be used in fireproofing wood and in disinfectants) and iron.
3Mg(s) + 2FeCl3 à 3MgCl2 + 2Fe(s)
A mixture of 41.0 g of magnesium(molar mass =24.31 g/mol) and 175 g of iron(III) chloride (molar mass=162.2 g/mol) is allowed to react. What mass of magnesium chloride(molar mass =95.21 g/mol)
a) 68.5 g MgCl2
b) 77.0 g MgCl2
c) 71.4 g MgCl2
d) 107 g MgCl2
e) 154 g MgCl2
Handwritten answers show how to find empirical formula and products formed for 2 multiple choice questions.
Mole, Empirical and Stoichiometry Calculations
Mole Calculations (Determining Avogadro's Number):
1. Calculate the mass of carbon in a diamond that contains 3.33 x 1024 atoms of C.
2. Calculate the mass of chloroform that contains 1,000,000,000,000 molecules of CHCL3.
3. Calculate the number of NaCL formula units in 1.37 g of table salt.
4. Calculate the number of N2 molecules in 0.111 g of nitrogen gas.
Empirical Formula Calculations (Compounds):
5. A 0.750 g sample of tin metal reacts with o.201 g of oxygen gas to form tin oxide.Calculate the empirical formula of tin Oxide.
6. A 0.565 g sample of cobalt metal reacts with excess sulfur to give 1.027 g of cobalt sulfide. Calculate the empirical formula of the product.
7. A 1.164-g sample of iron filings reacts with chlorine gas to give 3.384 g of iron chloride. Calculate the empirical formula of the product?
8. A 0.626 g sample of copper oxide was reduced to 0.500 g of copper metal by heating in a stream of hydrogen gas. Calculate the empirical formula of the copper oxide.
Stoichiometry Calculations (Precipitating Calcium Phosphate) :
9. A 0.914-g sample of stannous fluoride gives a 1.078-g precipitate of stannous phosphate. Calculate the theoretical yield and percent yield of Sn3(Po4)2.
10. A 10.000-g sample of toothpaste containing stannous fluoride gives a 0.145-g precipitate of stannous phosphate. What is the percentage of SnF2 in the toothpaste sample?