Chem Chap 1 online MCQ

Determine the molecular mass of iron(III) bromide hexahydrate, a substance used as a catalyst in organic reactions.

How many moles of ions are released when 0.27 mol of cobalt(III) chloride, CoCl2, is dissolved in water?

Lithium forms compounds which are used in dry cells and storage batteries and in high-temperature lubricants. It has two naturally occurring isotopes, 6Li (isotopic mass = 6.015121 amu) and 7Li (isotopic mass = 7.016003 amu). Lithium has an atomic mass of 6.9409 amu. What is the percent abundance of lithium-6?

In the combustion analysis of 0.1127 g of glucose (C6H12O6), what mass, in grams, of CO2 would be produced?

How many sodium ions are present in 325 mL of 0.850 M Na2SO4 ?

Terephthalic acid, used in the production of polyester fibers and films, is composed of carbon, hydrogen, and oxygen. When 0.6943 g of terephthalic acid was subjected to combustion analysis it produced 1.471 g CO2 and 0.226 g H2O. What is its empirical formula?

Different quantities of nitrogen oxide (NO) are listed below. Which one contains the LEAST number of molecules?

Hydroxylamine nitrate contains 29.17 mass % N, 4.20 mass % H, and 66.63 mass % O. Determine its empirical formula.

Terephthalic acid, used in the production of polyester fibers and films, is composed of carbon, hydrogen, and oxygen. If its molar mass is between 158 and 167 g/mol, what is its molecular formula?

Hydroxylamine nitrate contains 29.17 mass % N, 4.20 mass % H, and 66.63 mass O. If its molar mass is between 94 and 98 g/mol, what is its molecular formula?

Ammonium sulfate, (NH4)2SO4, is a fertilizer widely used as a source of nitrogen. Calculate its molecular mass.

Gadolinium oxide, a colorless powder which absorbs carbon dioxide from the air, contains 86.76 mass % Gd. Determine its empirical formula.

Silicon, which makes up about 25% of Earth's crust by mass, is used widely in the modern electronics industry. It has three naturally occurring isotopes, 28Si, 29Si, and 30Si. Calculate the atomic mass of silicon.

Isotope Isotopic Mass (amu) Abundance %
28Si 27.976927 92.23
29Si 28.976495 4.67
30Si 29.973770 3.10

Iodine pentafluoride reacts slowly with glass and violently with water. Determine its molecular mass.

In a particular experiment, to determine the RAM of a metal X, 3.27 g of X was completely reacted with oxygen to produce 4.07 g of the oxide of formula XO. The RAM of X is

Bromine is the only nonmetal that is a liquid at room temperature. Consider the isotope
bromine-81, . Select the combination which lists the correct atomic number, neutron number, and mass number, respectively.

How many moles of ions are released when 1.6 mol of ammonium phosphate, (NH4)3PO4, is dissolved in water?

5.00g of nitrogen is completely converted into an oxide of nitrogen. The mass of the oxide formed is 19.3g. The empirical formula of the oxide would be

An organic compound is known to contain only carbon, hydrogen and oxygen. The compound contains, by mass, 39.1% carbon and 8.7% hydrogen. The number of carbon atoms in the empirical formula is

Sodium chromate is used to protect iron from corrosion and rusting. Determine its molecular mass.