Test Prep: chapters 1-4
A chemist makes 140. mL of iron(II) bromide (FeBr2) working solution by adding distilled water to 30.0 mL of a 1.88 M stock solution of iron(II) bromide in water. Calculate the concentration of the chemist's working solution. Round your answer to 3 significant digits.
0.403 M
This is the chemical formula for methyl tert-butyl ether (the clean-fuel gasoline additive MTBE): CH3OCCH33 A chemical engineer has determined by measurements that there are 4.9 moles of hydrogen in a sample of methyl tert-butyl ether. How many moles of oxygen are in the sample? Round your answer to 2 significant digits.
0.41 mol
A chemist determined by measurements that 0.0200 moles of aluminum participated in a chemical reaction. Calculate the mass of aluminum that participated in the chemical reaction. Round your answer to 3 significant digits.
0.540 g
The chemical formula for barium oxide is BaO. A chemist measured the amount of barium oxide produced during an experiment. She finds that 3.7 g of barium oxide is produced. Calculate the number of moles of barium oxide produced. Round your answer to 2 significant digits.
2.4 x 10^-2
A chemist prepares a solution of mercury(I) chloride (Hg2Cl2) by measuring out. 0.000389 micro mol of mercury(I) chloride into a 150. mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in mol/L of the chemist's mercury(I) solution. Round your answer to 3 significant digits.
2.59 x 10^-9 mol/L
The chemical formula for potassium iodide is KI. A chemist determined by measurements that 0.0600 moles of potassium iodide participate in a chemical reaction. Calculate the mass of potassium iodide that participates. Round your answer to 3 significant digits.
9.96 g
Wine goes bad soon after opening because the ethanol (CH3CH2OH) dissolved in it reacts with oxygen (O2) gas to form water and aqueous acetic acid (CH3COOH), the main ingredient in vinegar. Calculate the moles of acetic acid produced by the reaction of 0.050mol of oxygen. Be sure your answer has a unit symbol, if necessary, and round it to 2 significant digits.
5.0 x 10^-2 mol
A virus has a mass of 9.0 x 10^-12 mg and an oil tanker has a mass of 3.0 x 10^7 kg. Use this information to answer the questions below. Be sure your answers have the correct number of significant digits. What is the mass of 1 mole of viruses? Round your answer to 2 significant digits.
5.4 x 10^9
A virus has a mass of 9.0 x 10^-12 mg and an oil tanker has a mass of 3.0 x 10^7 kg. Use this information to answer the questions below. Be sure your answers have the correct number of significant digits. How many moles of viruses have a mass equal to the mass of an oil tanker?Round your answer to 2 significant digits.
5.6 mol
Calculate the mass of dinitrogen tetroxide N2O4 that contains a billion 1.00 x 10^9 nitrogen atoms. Be sure your answer has a unit symbol if necessary, and round it to 3 significant digits.
7.64 x 10^-14
A chemist prepares a solution of potassium chloride (KCl) by measuring out 92.1 mg of KCl into a 300. mL volumetric flask and filling to the mark with distilled water. Calculate the molarity of Cl- anions in the chemist's solution. Be sure your answer is rouded to 3 significant digits.
0.00412 mol/L
Calculate the number of oxygen atoms in a 110.0g sample of iron(III) oxide (Fe2O3). Be sure your answer has a unit symbol if necessary, and round it to 4 significant digits.
1.244 x 10^24
A major component of gasoline is octane C8H18. When octane is burned in air, it chemically reacts with oxygen gas O2 to produce carbon dioxide CO2 and water H2O. What mass of octane is consumed by the reaction of 5.97g of oxygen gas? Round your answer to 3 significant digits.
1.71 g of octane
Green plants use light from the Sun to drive photosynthesis. Photosynthesis is a chemical reaction in which water (H2O) and carbon dioxide CO2 chemically react to form the simple sugar glucose C6H12O6 and oxygen gas O2. What mass of simple sugar glucose is produced by the reaction of 4.63g of water? Round your answer to 3 significant digits.
7.72 g
Calculate the volume in liters of a 0.00697 micro M calcium sulfate solution that contains 6.00 mol of calcium sulfate (CaSO4). Round your answer to 3 significant digits.
8.61 x 10^8 L
An unknown compound has the following chemical formula: FeNO3x where x stands for a whole number. Measurements also show that a certain sample of the unknown compound contains 9.10mol of nitrogen and 3.0mol of iron. Write the complete chemical formula for the unknown compound. FeNO33
Fe(NO3)3
An unknown compound has the following chemical formula: NxO where x stands for a whole number. Measurements also show that a certain sample of the unknown compound contains 7.70mol of nitrogen and 3.9mol of oxygen. Write the complete chemical formula for the unknown compound.
N2O