Chemistry 2202 Unit 1Section 2 HWPPage 1 of 2
CHEMISTRY 2202
Unit 1Section 2Homework Portfolio
Value
- Aluminum reacts with oxygen to produce aluminium oxide according to the formula:
(2)(a)Using proper chemical names for all species, write sentences to show how this equation should be read:
- in terms of moles and
- in terms of representative particles (atoms, molecules, ions).
(2)(b)Using appropriate calculations, demonstrate that the balanced chemical equation supports the Law of Conservation of Mass.
(1)2.(a)What is a mole ratio?
(1)(b)What is stoichiometry?
(1)(c)Why do we need to use mole ratios in stoichiometry?
(3)3. Rewrite and complete the table of mole ratios for the reaction:
NH3 / O2 / H2O / NO2a. / 2.00 mol
b. / 1.50 mol
c. / 0.750 mol
4.Methanol, CH3OH is produced industrially and is used as antifreeze and as a fuel source. The final step in the production of liquid methanol is the reaction of carbon monoxide gas with hydrogen gas.
(1)(a)Write a balanced chemical equation for the reaction.
(1.5)(b)Calculate the number of moles of carbon monoxide gas that is required to react with 8.68 mol of methanol.
(1.5)(c)Calculate the number of moles of methanol that should be produced from the complete reaction of 54 kmol of hydrogen gas.
(3)5.A spectacular exothermic reaction occurs when ammonium dichromate is heated. The reaction that occurs is shown by the following equation.
What mass of water vapour will be produced when 2.55 g of (NH4)2Cr2O7(s) decomposes?
6.Butane burns completely in air to produce carbon dioxide and water vapour.
(2)(a)Calculate the volume of oxygen gas that should react with 1.25 L of propane gas at STP condition.
(3)(b)Calculate the volume of carbon dioxide gas (at STP) that should be produced by the complete combustion of 375 g of butane.
7.The following single displacement reaction occurs when the solid mixture of aluminium and manganese(II) oxide are heated.
(3)(a) Perform calculations to identify the excess and limiting specieswhen 50.00 g of Al(s) and 90.00 g of MnO(s) are allowed to react?
(1)(b)Based on the limiting reagent found in (a), what mass of manganese should be produced?
(1)(c)What is the percent yield if 62.5 g of manganese was actually produced?
(3)8.Classify each observation as either random error or systematic error.
(a)You are sitting in the passenger’s seat and observe that your dad is only driving 80 kmh on the Trans Canada highway. You ask him to speed up and he says he is already driving 100kmh.
(b)You catch a large salmon and weigh it on two different scales. One scale gives you a mass of 1.8 kg and the other scale gives a mass of 2.3 kg.
(c)The procedure of a lab says to weigh a mass of 2.5 g of potassium nitrate in a clean dry beaker. When you clean the beaker you forget to dry it, leaving drops of water on the sides of the beaker.
- An experiment was carried out in which a piece of magnesium metal was gently dropped into to a beaker of hydrochloric acid. The hydrogen gas produced during the reaction was collected at SATP conditions.
The mass of magnesium was recorded before and after the reaction.
Mass of Mg before reaction: 23.45g
Mass of Mg after reaction:21.64g
(3)(a)Calculate the theoretical yield of hydrogen gas.
(1)(b)Calculate the percent yield If 1.55 L of hydrogen gas was actually collected under SATP conditions.
(1)(c)Give two possible reasons why the percent yield is not 100%