Reference no: EM131125127

Chemical React ions

Measurement and the Mole

Before you begin, go to the package titled "Test Study Guides & Reference Materials". Remove the "The Periodic Table" sheet, the "Symbols & Oxidation Numbers" sheet, and the "Solubilities & Activity Series" sheet. Don't forget to return them to the original package when finished because they will be used on other tests.

Please write your name in the space shown at the top of this page.

 

When finished, please fill in the date and time taken to write the test.

 

It should take an average student approximately one hour to complete, but it is acceptable to use more time if needed.

 

Short answer or parts of questions (a or b...) are worth 2 marks each. Other mark values are shown in brackets after the question. Page totals: 24, 23, 30, 17.

 

You may write in pencil as long as the imprint is not faint.

 

You will need a calculator and scrap paper for rough work.

 

You may not have access to any materials, written or otherwise, which may assist you in answering the questions. Academic honesty is expected.

 

Whenever a line is drawn for the insertion of an answer, without space allowed for calculations, no model solution is required. Work out the answer on scrap paper, then enter it in the space provided. All other questions require model answers or solutions.

 

All final numerical answers must be expressed in scientific notation to the correct number of significant figures.

 

The following relationships will be required.

1.000 mol º N particles º mass of 1 mole

Avogadro's Number, N = 6.023 x 10²³
QR = QG x UF(s)

 

MM = m / n
Factor = mfMM / sfMM

 

1.

a) Define a precipitate.

 

b) As an example, consider the reaction between solutions of magnesium chloride and silver (I) nitrate.  Write the word equation here.

 

c) Write the balanced overall (molecular) equation for the above reaction. Identify the precipitate. (this is the chemical equation)

 

d) Write the balanced net ionic equation for the above reaction. Identify the precipitate.

 

2. Write the balanced chemical equation for each of the following:

 

a) Postassium burns readily in the presence of oxygen gas in a synthesis reaction.

 

b) Aluminum replaces the iron in iron (III) oxide in the thermite reaction.

 

3. Complete and balance each of following overall (molecular) equations if it occurs. Below each, write the balanced net ionic equation.

 

a) Ca (s) + Al(NO₃)₃ (aq) →

 

b) Net:

 

c) KBr (aq) + Cl₂ (g) →

 

d) Net:

 

e) Au (s) + AgNO₃ →

f) Net:

 

4.

a) Define the term neutralization.

b) As an example, write the word equation for the production of barium sulphate by the neutralization of the appropriate acid and base.

c) Convert the above equation to its balanced chemical equation.

d) Write the net ionic equation that occurs in any neutralization reaction.

5. Complete the following chart.

 

 

Characteristic or Property	Alpha Rays	Beta Rays	Gamma Rays
Symbol (Greek)
Attraction to a negatively charged plate (Attracted/Repelled/None)
Mass (none/small/large)
Penetrating ability (small/large)

 

6.

a) Balance the nuclear equation below.

 

²⁴₁₁Na → +²⁴₁₂Mg

 

b) Is the above transmutation an alpha or beta decay?  ________________

 

c) Balance the nuclear equation below.

²¹⁴₈₄Po → +²¹⁰₈₂Pb

 

d) Is the above transmutation an alpha or beta decay?  ________________

 

7. Convert 502 miles to metres given 1.00 mi = 1.609 km. Develop a model solution using the method of unit analysis. Express the answer in scientific notation to the    correct number of significant figures.

8. A cylindrical gas lecture bottle has internal dimensions of 18.0 cm in diameter and a height of 49.0 cm and weighs 1.75 kg when empty. It is designed to hold compressed gas and weighs 3.75 when full of oxygen gas. What is the density of the oxygen gas in the full bottle? (8)

Convert the volume to m³.  Develop a model solution. V = π r² h; D = m/V

 

9.

a) How many atoms of gold, 79-Au are contained in 1.75 moles of it? ....................   .............. __________

 

b) How many grams do 9.1 x 10²⁴ atoms of  carbon 14 weigh?  ........ ___________

 

c) How many moles of cesium are contained in 2.50 x 10^-6 g of it.   ___________

 

d) If 0.250 mol of a certain element has a mass of 51.8 g, what is its molar mass? .................. _______ This element is a member of group IVA. What is its name? ................. ____________

 

e) What is the mass of 0.75 moles of tungsten, 74W?

 

f) What mass of oxygen is contained in 155 g of Ca₃(PO₄)₂?

 

10. A compound contains 27 % carbon and 73% oxygen by mass.

 

a) Determine the simplest formula.

 

b) If one mole of this compound has a mass of 44 g, what is the actual molecular formula of this compound?

 

c) A related binary compound of these same two elements has a molar mass of 28 g. What is its molecular formula?________

 

d) Which of these two possible compounds (from b and c) is implicated in human aggravated global warming? ___________

 

11.

a) What is the percentage composition of glucose, C₆H₁₂O₆? Round percentages correct to the first decimal place.

 

b) Acetic acid has the same simplest formula as glucose but only 1/3 of the molar mass. Find its molecular formula.