Stoichiometric Calculations Quiz

The chemical equation below shows the reaction between tin (Sn) and hydrogen fluoride (HF). Sn + 2HF mc017-1.jpg SnF2 + H2 The molar mass of HF is 20.01 g/mol. How many moles of Sn are required to react with 40 g of HF?

A. 1

The chemical equation below shows the photosynthesis reaction. 6CO2 + 6H2O mc010-1.jpg C6H12O6 + 6O2 The molar mass of carbon dioxide (CO2) is 44.01 g/mol. The molar mass of water (H2O) is 18.01 g/mol. A reaction uses 528 g of CO2. How many moles of water are used in this reaction?

A. 12.0

Air is about 78% nitrogen gas (N2) by mass. The molar mass of nitrogen gas is 28.0 g/mol. A 100.0-g sample of air contains how many moles of nitrogen?

A. 2.8

The Haber process can be used to produce ammonia (NH3) from hydrogen gas (H2) and nitrogen gas (N2). The balanced equation for this process is shown below. 3H2 + N2 mc025-1.jpg 2NH3 The molar mass of NH3 is 17.03 g/mol. The molar mass of H2 is 2.0158 g/mol. In a particular reaction, 0.575 g of NH3 forms. What is the mass, in grams, of H2 that must have reacted, to the correct number of significant figures?

B. 0.102

A student has a sample of isopropanol (C3H7OH) that has a mass of 78.6 g. The molar mass of isopropanol is 60.1 g/mol. How many moles of isopropanol are contained in this sample?

B. 1.31

The chemical equation below shows the burning of magnesium (Mg) with oxygen (O2) to form magnesium oxide (MgO). 2Mg + O2 mc019-1.jpg 2MgO Niven wants to calculate the mass of MgO that is produced by the burning of 28.0 g of Mg. What is the first step in Niven's calculation?

B. Convert grams of Mg to moles.

The chemical equation below shows the decomposition of nitrogen triiodide (NI3) into nitrogen (N2) and iodine (I2). 2NI3 mc030-1.jpg N2 + 3I2 The molar mass of I2 is 253.80 g/mol, and the molar mass of NI3 is 394.71 g/mol. How many moles of I2 will form 3.58 g of NI3?

C. 0.0136

The chemical equation below shows the reaction between carbon dioxide (CO2) and lithium hydroxide (LiOH). CO2 + 2LiOH mc011-1.jpg Li2CO3 + H2O The molar mass CO2 is 44.01 g/mol. How many moles of LiOH are needed to react completely with 25.5 g of CO2?

C. 1.16

Mercury(II) oxide (HgO) decomposes to form mercury (Hg) and oxygen (O2). The balanced chemical equation is shown below. 2HgO mc020-1.jpg 2Hg + O2 The molar mass of HgO is 216.59 g/mol. The molar mass of O2 is 32.00 g/mol. How many moles of HgO are needed to produce 250.0 g of O2?

C. 15.63

Lakshmi has a sample of ammonium nitrate (NH4NO3) that has a mass of 40.10 g. She knows that the molar mass of NH4NO3 is 80.0432 g/mol. To the correct number of significant digits, how many moles of NH4NO3 does the sample contain?

D. 0.5010

The molar mass of nitrogen (N2) is 28.02 g/mol. What is the mass, in grams, of 4.60 mol of N2?

D. 129

Passing an electric current through a sample of water (H2O) can cause the water to decompose into hydrogen gas (H2) and oxygen gas (O2) according to the following equation. 2H2O mc026-1.jpg 2H2 + O2 The molar mass of H2O is 18.01 g/mol. The molar mass of O2 is 32.00 g/mol. What mass of H2O, in grams, must react to produce 50.00 g of O2?

D. 56.28

A chemist has 2.0 mol of methanol (CH3OH). The molar mass of methanol is 32.0 g/mol. What is the mass, in grams, of the sample?

D. 64

The molar mass of hydrogen (H2) is 2.02 g/mol. A sample contains 4.00 mol of H2. What is the mass, in grams, of this sample?

D. 8.08